vim: runtime/doc/vim9.txt annotate

annotate runtime/doc/vim9.txt @ 35145:8b9f22608aa5 default tip

Added tag v9.1.0401 for changeset 2179990b5be67c94e17f829ebd64bcc0cee920ee

author	Christian Brabandt <cb@256bit.org>
date	Thu, 09 May 2024 20:45:04 +0200
parents	8c9e43278b2c
children

rev	line source
34907 8c9e43278b2c patch 9.1.0314: Vim9: Can define a class in a function Christian Brabandt <cb@256bit.org> parents: 34902 diff changeset	1 vim9.txt For Vim version 9.1. Last change: 2024 Apr 13
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	3
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	4 VIM REFERENCE MANUAL by Bram Moolenaar
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	5
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	6
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	7 Vim9 script commands and expressions. Vim9 vim9
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	8
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	9 Most expression help is in \|eval.txt\|. This file is about the new syntax and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	10 features in Vim9 script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	11
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	12
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	13
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	14 1. What is Vim9 script? \|Vim9-script\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	15 2. Differences \|vim9-differences\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	16 3. New style functions \|fast-functions\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	17 4. Types \|vim9-types\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	18 5. Namespace, Import and Export \|vim9script\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	19 6. Classes and interfaces \|vim9-classes\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	20
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	21 9. Rationale \|vim9-rationale\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	22
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	23 ==============================================================================
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	24
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	25 1. What is Vim9 script? Vim9-script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	26
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	27 Vim script has been growing over time, while preserving backwards
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	28 compatibility. That means bad choices from the past often can't be changed
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	29 and compatibility with Vi restricts possible solutions. Execution is quite
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	30 slow, each line is parsed every time it is executed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	31
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	32 The main goal of Vim9 script is to drastically improve performance. This is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	33 accomplished by compiling commands into instructions that can be efficiently
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	34 executed. An increase in execution speed of 10 to 100 times can be expected.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	35
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	36 A secondary goal is to avoid Vim-specific constructs and get closer to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	37 commonly used programming languages, such as JavaScript, TypeScript and Java.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	38
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	39 The performance improvements can only be achieved by not being 100% backwards
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	40 compatible. For example, making function arguments available in the "a:"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	41 dictionary adds quite a lot of overhead. In a Vim9 function this dictionary
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	42 is not available. Other differences are more subtle, such as how errors are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	43 handled.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	44
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	45 The Vim9 script syntax and semantics are used in:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	46 - a function defined with the `:def` command
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	47 - a script file where the first command is `vim9script`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	48 - an autocommand defined in the context of the above
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	49 - a command prefixed with the `vim9cmd` command modifier
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	50
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	51 When using `:function` in a Vim9 script file the legacy syntax is used, with
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	52 the highest \|scriptversion\|. However, this can be confusing and is therefore
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	53 discouraged.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	54
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	55 Vim9 script and legacy Vim script can be mixed. There is no requirement to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	56 rewrite old scripts, they keep working as before. You may want to use a few
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	57 `:def` functions for code that needs to be fast.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	58
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	59 :vim9[cmd] {cmd} :vim9 :vim9cmd E1164
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	60 Evaluate and execute {cmd} using Vim9 script syntax and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	61 semantics. Useful when typing a command and in a legacy
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	62 script or function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	63
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	64 :leg[acy] {cmd} :leg :legacy E1189 E1234
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	65 Evaluate and execute {cmd} using legacy script syntax and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	66 semantics. Only useful in a Vim9 script or a :def function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	67 Note that {cmd} cannot use local variables, since it is parsed
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	68 with legacy expression syntax.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	69
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	70 ==============================================================================
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	71
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	72 2. Differences from legacy Vim script vim9-differences
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	73
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	74 Overview ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	75 E1146
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	76 Brief summary of the differences you will most often encounter when using Vim9
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	77 script and `:def` functions; details are below:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	78 - Comments start with #, not ": >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	79 echo "hello" # comment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	80 - Using a backslash for line continuation is hardly ever needed: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	81 echo "hello "
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	82 .. yourName
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	83 .. ", how are you?"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	84 - White space is required in many places to improve readability.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	85 - Assign values without `:let` E1126 , declare variables with `:var`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	86 var count = 0
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	87 count += 3
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	88 - Constants can be declared with `:final` and `:const`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	89 final matches = [] # add to the list later
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	90 const names = ['Betty', 'Peter'] # cannot be changed
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	91 - `:final` cannot be used as an abbreviation of `:finally`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	92 - Variables and functions are script-local by default.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	93 - Functions are declared with argument types and return type: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	94 def CallMe(count: number, message: string): bool
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	95 - Call functions without `:call`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	96 writefile(['done'], 'file.txt')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	97 - You cannot use old Ex commands:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	98 `:Print`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	99 `:append`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	100 `:change`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	101 `:d` directly followed by 'd' or 'p'.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	102 `:insert`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	103 `:k`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	104 `:mode`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	105 `:open`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	106 `:s` with only flags
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	107 `:t`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	108 `:xit`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	109 - Some commands, especially those used for flow control, cannot be shortened.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	110 E.g., `:throw` cannot be written as `:th`. vim9-no-shorten
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	111 - You cannot use curly-braces names.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	112 - A range before a command must be prefixed with a colon: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	113 :%s/this/that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	114 - Executing a register with "@r" does not work, you can prepend a colon or use
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	115 `:exe`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	116 :exe @a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	117 - Unless mentioned specifically, the highest \|scriptversion\| is used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	118 - When defining an expression mapping, the expression will be evaluated in the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	119 context of the script where it was defined.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	120 - When indexing a string the index is counted in characters, not bytes:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	121 \|vim9-string-index\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	122 - Some possibly unexpected differences: \|vim9-gotchas\|.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	123
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	124
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	125 Comments starting with # ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	126
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	127 In legacy Vim script comments start with double quote. In Vim9 script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	128 comments start with #. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	129 # declarations
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	130 var count = 0 # number of occurrences
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	131
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	132 The reason is that a double quote can also be the start of a string. In many
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	133 places, especially halfway through an expression with a line break, it's hard
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	134 to tell what the meaning is, since both a string and a comment can be followed
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	135 by arbitrary text. To avoid confusion only # comments are recognized. This
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	136 is the same as in shell scripts and Python programs.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	137
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	138 In Vi # is a command to list text with numbers. In Vim9 script you can use
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	139 `:number` for that. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	140 :101 number
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	141
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	142 To improve readability there must be a space between a command and the #
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	143 that starts a comment: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	144 var name = value # comment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	145 var name = value# error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	146 < E1170
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	147 Do not start a comment with #{, it looks like the legacy dictionary literal
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	148 and produces an error where this might be confusing. #{{ or #{{{ are OK,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	149 these can be used to start a fold.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	150
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	151 When starting to read a script file Vim doesn't know it is \|Vim9\| script until
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	152 the `vim9script` command is found. Until that point you would need to use
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	153 legacy comments: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	154 " legacy comment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	155 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	156 # Vim9 comment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	157
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	158 That looks ugly, better put `vim9script` in the very first line: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	159 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	160 # Vim9 comment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	161
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	162 In legacy Vim script # is also used for the alternate file name. In Vim9
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	163 script you need to use %% instead. Instead of ## use %%% (stands for all
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	164 arguments).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	165
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	166
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	167 Vim9 functions ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	168 E1099
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	169 A function defined with `:def` is compiled. Execution is many times faster,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	170 often 10 to 100 times.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	171
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	172 Many errors are already found when compiling, before the function is executed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	173 The syntax is strict, to enforce code that is easy to read and understand.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	174
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	175 Compilation is done when any of these is encountered:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	176 - the first time the function is called
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	177 - when the `:defcompile` command is encountered in the script after the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	178 function was defined
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	179 - `:disassemble` is used for the function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	180 - a function that is compiled calls the function or uses it as a function
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	181 reference (so that the argument and return types can be checked)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	182 E1091 E1191
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	183 If compilation fails it is not tried again on the next call, instead this
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	184 error is given: "E1091: Function is not compiled: {name}".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	185 Compilation will fail when encountering a user command that has not been
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	186 created yet. In this case you can call `execute()` to invoke it at runtime. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	187 def MyFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	188 execute('DefinedLater')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	189 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	190
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	191 `:def` has no options like `:function` does: "range", "abort", "dict" or
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	192 "closure". A `:def` function always aborts on an error (unless `:silent!` was
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	193 used for the command or the error was caught a `:try` block), does not get a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	194 range passed, cannot be a "dict" function, and can always be a closure.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	195 vim9-no-dict-function
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	196 You can use a Vim9 Class (\|Vim9-class\|) instead of a "dict function".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	197 You can also pass the dictionary explicitly: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	198 def DictFunc(self: dict<any>, arg: string)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	199 echo self[arg]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	200 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	201 var ad = {item: 'value', func: DictFunc}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	202 ad.func(ad, 'item')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	203
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	204 You can call a legacy dict function though: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	205 func Legacy() dict
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	206 echo self.value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	207 endfunc
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	208 def CallLegacy()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	209 var d = {func: Legacy, value: 'text'}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	210 d.func()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	211 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	212 < E1096 E1174 E1175
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	213 The argument types and return type need to be specified. The "any" type can
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	214 be used, type checking will then be done at runtime, like with legacy
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	215 functions.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	216 E1106
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	217 Arguments are accessed by name, without "a:", just like any other language.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	218 There is no "a:" dictionary or "a:000" list.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	219 vim9-variable-arguments E1055 E1160 E1180
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	220 Variable arguments are defined as the last argument, with a name and have a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	221 list type, similar to TypeScript. For example, a list of numbers: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	222 def MyFunc(...itemlist: list<number>)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	223 for item in itemlist
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	224 ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	225
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	226 When a function argument is optional (it has a default value) passing `v:none`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	227 as the argument results in using the default value. This is useful when you
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	228 want to specify a value for an argument that comes after an argument that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	229 should use its default value. Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	230 def MyFunc(one = 'one', last = 'last')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	231 ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	232 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	233 MyFunc(v:none, 'LAST') # first argument uses default value 'one'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	234 <
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	235 vim9-ignored-argument E1181
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	236 The argument "_" (an underscore) can be used to ignore the argument. This is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	237 most useful in callbacks where you don't need it, but do need to give an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	238 argument to match the call. E.g. when using map() two arguments are passed,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	239 the key and the value, to ignore the key: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	240 map(numberList, (_, v) => v * 2)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	241 There is no error for using the "_" argument multiple times. No type needs to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	242 be given.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	243
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	244
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	245 Functions and variables are script-local by default ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	246 vim9-scopes
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	247 When using `:function` or `:def` to specify a new function at the script level
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	248 in a Vim9 script, the function is local to the script. Like prefixing "s:" in
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	249 legacy script. To define a global function or variable the "g:" prefix must
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	250 be used. For functions in a script that is to be imported and in an autoload
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	251 script "export" needs to be used for those to be used elsewhere. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	252 def ThisFunction() # script-local
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	253 def g:ThatFunction() # global
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	254 export def Function() # for import and import autoload
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	255 < E1058 E1075
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	256 When using `:function` or `:def` to specify a nested function inside a `:def`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	257 function and no namespace was given, this nested function is local to the code
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	258 block it is defined in. It cannot be used in `function()` with a string
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	259 argument, pass the function reference itself: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	260 def Outer()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	261 def Inner()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	262 echo 'inner'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	263 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	264 var Fok = function(Inner) # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	265 var Fbad = function('Inner') # does not work
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	266
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	267 Detail: this is because "Inner" will actually become a function reference to a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	268 function with a generated name.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	269
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	270 It is not possible to define a script-local function in a function. You can
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	271 define a local function and assign it to a script-local Funcref (it must have
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	272 been declared at the script level). It is possible to define a global
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	273 function by using the "g:" prefix.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	274
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	275 When referring to a function and no "s:" or "g:" prefix is used, Vim will
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	276 search for the function:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	277 - in the function scope, in block scopes
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	278 - in the script scope
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	279
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	280 Imported functions are found with the prefix from the `:import` command.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	281
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	282 Since a script-local function reference can be used without "s:" the name must
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	283 start with an upper case letter even when using the "s:" prefix. In legacy
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	284 script "s:funcref" could be used, because it could not be referred to with
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	285 "funcref". In Vim9 script it can, therefore "s:Funcref" must be used to avoid
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	286 that the name interferes with builtin functions.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	287 vim9-s-namespace E1268
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	288 The use of the "s:" prefix is not supported at the Vim9 script level. All
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	289 functions and variables without a prefix are script-local.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	290
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	291 In :def functions the use of "s:" depends on the script: Script-local
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	292 variables and functions in a legacy script do use "s:", while in a Vim9 script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	293 they do not use "s:". This matches what you see in the rest of the file.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	294
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	295 In legacy functions the use of "s:" for script items is required, as before.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	296 No matter if the script is Vim9 or legacy.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	297
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	298 In all cases the function must be defined before used. That is when it is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	299 called, when `:defcompile` causes it to be compiled, or when code that calls
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	300 it is being compiled (to figure out the return type).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	301
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	302 The result is that functions and variables without a namespace can usually be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	303 found in the script, either defined there or imported. Global functions and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	304 variables could be defined anywhere (good luck finding out where! You can
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	305 often see where it was last set using \|:verbose\|).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	306 E1102
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	307 Global functions can still be defined and deleted at nearly any time. In
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	308 Vim9 script script-local functions are defined once when the script is sourced
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	309 and cannot be deleted or replaced by itself (it can be by reloading the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	310 script).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	311
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	312 When compiling a function and a function call is encountered for a function
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	313 that is not (yet) defined, the \|FuncUndefined\| autocommand is not triggered.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	314 You can use an autoload function if needed, or call a legacy function and have
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	315 \|FuncUndefined\| triggered there.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	316
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	317
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	318 Reloading a Vim9 script clears functions and variables by default ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	319 vim9-reload E1149 E1150
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	320 When loading a legacy Vim script a second time nothing is removed, the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	321 commands will replace existing variables and functions, create new ones, and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	322 leave removed things hanging around.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	323
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	324 When loading a Vim9 script a second time all existing script-local functions
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	325 and variables are deleted, thus you start with a clean slate. This is useful
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	326 if you are developing a plugin and want to try a new version. If you renamed
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	327 something you don't have to worry about the old name still hanging around.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	328
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	329 If you do want to keep items, use: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	330 vim9script noclear
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	331
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	332 You want to use this in scripts that use a `finish` command to bail out at
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	333 some point when loaded again. E.g. when a buffer local option is set to a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	334 function, the function does not need to be defined more than once: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	335 vim9script noclear
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	336 setlocal completefunc=SomeFunc
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	337 if exists('*SomeFunc')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	338 finish
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	339 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	340 def SomeFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	341 ....
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	342
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	343
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	344 Variable declarations with :var, :final and :const ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	345 vim9-declaration :var E1079
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	346 E1017 E1020 E1054 E1087 E1124
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	347 Local variables need to be declared with `:var`. Local constants need to be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	348 declared with `:final` or `:const`. We refer to both as "variables" in this
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	349 section.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	350
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	351 Variables can be local to a script, function or code block: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	352 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	353 var script_var = 123
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	354 def SomeFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	355 var func_var = script_var
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	356 if cond
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	357 var block_var = func_var
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	358 ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	359
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	360 The variables are only visible in the block where they are defined and nested
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	361 blocks. Once the block ends the variable is no longer accessible: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	362 if cond
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	363 var inner = 5
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	364 else
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	365 var inner = 0
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	366 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	367 echo inner # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	368
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	369 The declaration must be done earlier: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	370 var inner: number
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	371 if cond
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	372 inner = 5
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	373 else
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	374 inner = 0
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	375 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	376 echo inner
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	377
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	378 Although this is shorter and faster for simple values: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	379 var inner = 0
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	380 if cond
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	381 inner = 5
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	382 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	383 echo inner
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	384 < E1025 E1128
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	385 To intentionally hide a variable from code that follows, a block can be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	386 used: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	387 {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	388 var temp = 'temp'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	389 ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	390 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	391 echo temp # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	392
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	393 This is especially useful in a user command: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	394 command -range Rename {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	395 var save = @a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	396 @a = 'some expression'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	397 echo 'do something with ' .. @a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	398 @a = save
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	399 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	400
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	401 And with autocommands: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	402 au BufWritePre *.go {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	403 var save = winsaveview()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	404 silent! exe ':%! some formatting command'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	405 winrestview(save)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	406 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	407
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	408 Although using a :def function probably works better.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	409
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	410 E1022 E1103 E1130 E1131 E1133
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	411 E1134
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	412 Declaring a variable with a type but without an initializer will initialize to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	413 false (for bool), empty (for string, list, dict, etc.) or zero (for number,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	414 any, etc.). This matters especially when using the "any" type, the value will
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	415 default to the number zero. For example, when declaring a list, items can be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	416 added: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	417 var myList: list<number>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	418 myList->add(7)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	419
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	420 Initializing a variable to a null value, e.g. `null_list`, differs from not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	421 initializing the variable. This throws an error: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	422 var myList = null_list
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	423 myList->add(7) # E1130: Cannot add to null list
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	424
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	425 < E1016 E1052 E1066
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	426 In Vim9 script `:let` cannot be used. An existing variable is assigned to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	427 without any command. The same for global, window, tab, buffer and Vim
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	428 variables, because they are not really declared. Those can also be deleted
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	429 with `:unlet`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	430 E1065
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	431 You cannot use `:va` to declare a variable, it must be written with the full
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	432 name `:var`. Just to make sure it is easy to read.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	433 E1178
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	434 `:lockvar` does not work on local variables. Use `:const` and `:final`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	435 instead.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	436
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	437 The `exists()` and `exists_compiled()` functions do not work on local variables
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	438 or arguments.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	439 E1006 E1041 E1167 E1168 E1213
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	440 Variables, functions and function arguments cannot shadow previously defined
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	441 or imported variables and functions in the same script file.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	442 Variables may shadow Ex commands, rename the variable if needed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	443
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	444 Global variables must be prefixed with "g:", also at the script level. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	445 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	446 var script_local = 'text'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	447 g:global = 'value'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	448 var Funcref = g:ThatFunction
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	449
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	450 Global functions must be prefixed with "g:": >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	451 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	452 def g:GlobalFunc(): string
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	453 return 'text'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	454 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	455 echo g:GlobalFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	456 The "g:" prefix is not needed for auto-load functions.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	457
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	458 vim9-function-defined-later
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	459 Although global functions can be called without the "g:" prefix, they must
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	460 exist when compiled. By adding the "g:" prefix the function can be defined
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	461 later. Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	462 def CallPluginFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	463 if exists('g:loaded_plugin')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	464 g:PluginFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	465 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	466 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	467
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	468 If you do it like this, you get an error at compile time that "PluginFunc"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	469 does not exist, even when "g:loaded_plugin" does not exist: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	470 def CallPluginFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	471 if exists('g:loaded_plugin')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	472 PluginFunc() # Error - function not found
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	473 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	474 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	475
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	476 You can use exists_compiled() to avoid the error, but then the function would
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	477 not be called, even when "g:loaded_plugin" is defined later: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	478 def CallPluginFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	479 if exists_compiled('g:loaded_plugin')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	480 PluginFunc() # Function may never be called
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	481 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	482 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	483
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	484 Since `&opt = value` is now assigning a value to option "opt", ":&" cannot be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	485 used to repeat a `:substitute` command.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	486 vim9-unpack-ignore
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	487 For an unpack assignment the underscore can be used to ignore a list item,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	488 similar to how a function argument can be ignored: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	489 [a, _, c] = theList
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	490 To ignore any remaining items: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	491 [a, b; _] = longList
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	492 < E1163 E1080
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	493 Declaring more than one variable at a time, using the unpack notation, is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	494 possible. Each variable can have a type or infer it from the value: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	495 var [v1: number, v2] = GetValues()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	496 Use this only when there is a list with values, declaring one variable per
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	497 line is much easier to read and change later.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	498
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	499
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	500 Constants ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	501 vim9-const vim9-final
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	502 How constants work varies between languages. Some consider a variable that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	503 can't be assigned another value a constant. JavaScript is an example. Others
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	504 also make the value immutable, thus when a constant uses a list, the list
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	505 cannot be changed. In Vim9 we can use both.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	506 E1021 E1307
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	507 `:const` is used for making both the variable and the value a constant. Use
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	508 this for composite structures that you want to make sure will not be modified.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	509 Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	510 const myList = [1, 2]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	511 myList = [3, 4] # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	512 myList[0] = 9 # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	513 myList->add(3) # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	514 < :final E1125
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	515 `:final` is used for making only the variable a constant, the value can be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	516 changed. This is well known from Java. Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	517 final myList = [1, 2]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	518 myList = [3, 4] # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	519 myList[0] = 9 # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	520 myList->add(3) # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	521
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	522 It is common to write constants as ALL_CAPS, but you don't have to.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	523
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	524 The constant only applies to the value itself, not what it refers to. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	525 final females = ["Mary"]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	526 const NAMES = [["John", "Peter"], females]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	527 NAMES[0] = ["Jack"] # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	528 NAMES[0][0] = "Jack" # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	529 NAMES[1] = ["Emma"] # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	530 NAMES[1][0] = "Emma" # OK, now females[0] == "Emma"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	531
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	532
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	533 Omitting :call and :eval ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	534 E1190
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	535 Functions can be called without `:call`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	536 writefile(lines, 'file')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	537 Using `:call` is still possible, but this is discouraged.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	538
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	539 A method call without `eval` is possible, so long as the start is an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	540 identifier or can't be an Ex command. For a function either "(" or "->" must
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	541 be following, without a line break. Examples: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	542 myList->add(123)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	543 g:myList->add(123)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	544 [1, 2, 3]->Process()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	545 {a: 1, b: 2}->Process()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	546 "foobar"->Process()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	547 ("foobar")->Process()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	548 'foobar'->Process()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	549 ('foobar')->Process()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	550
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	551 In the rare case there is ambiguity between a function name and an Ex command,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	552 prepend ":" to make clear you want to use the Ex command. For example, there
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	553 is both the `:substitute` command and the `substitute()` function. When the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	554 line starts with `substitute(` this will use the function. Prepend a colon to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	555 use the command instead: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	556 :substitute(pattern (replacement (
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	557
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	558 If the expression starts with "!" this is interpreted as a shell command, not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	559 negation of a condition. Thus this is a shell command: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	560 !shellCommand->something
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	561 Put the expression in parentheses to use the "!" for negation: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	562 (!expression)->Method()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	563
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	564 Note that while variables need to be defined before they can be used,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	565 functions can be called before being defined. This is required to allow
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	566 for cyclic dependencies between functions. It is slightly less efficient,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	567 since the function has to be looked up by name. And a typo in the function
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	568 name will only be found when the function is called.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	569
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	570
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	571 Omitting function() ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	572
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	573 A user defined function can be used as a function reference in an expression
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	574 without `function()`. The argument types and return type will then be checked.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	575 The function must already have been defined. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	576
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	577 var Funcref = MyFunction
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	578
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	579 When using `function()` the resulting type is "func", a function with any
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	580 number of arguments and any return type (including void). The function can be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	581 defined later if the argument is in quotes.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	582
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	583
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	584 Lambda using => instead of -> ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	585 vim9-lambda
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	586 In legacy script there can be confusion between using "->" for a method call
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	587 and for a lambda. Also, when a "{" is found the parser needs to figure out if
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	588 it is the start of a lambda or a dictionary, which is now more complicated
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	589 because of the use of argument types.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	590
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	591 To avoid these problems Vim9 script uses a different syntax for a lambda,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	592 which is similar to JavaScript: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	593 var Lambda = (arg) => expression
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	594 var Lambda = (arg): type => expression
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	595 < E1157
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	596 No line break is allowed in the arguments of a lambda up to and including the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	597 "=>" (so that Vim can tell the difference between an expression in parentheses
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	598 and lambda arguments). This is OK: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	599 filter(list, (k, v) =>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	600 v > 0)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	601 This does not work: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	602 filter(list, (k, v)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	603 => v > 0)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	604 This also does not work: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	605 filter(list, (k,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	606 v) => v > 0)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	607 But you can use a backslash to concatenate the lines before parsing: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	608 filter(list, (k,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	609 \ v)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	610 \ => v > 0)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	611 < vim9-lambda-arguments E1172
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	612 In legacy script a lambda could be called with any number of extra arguments,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	613 there was no way to warn for not using them. In Vim9 script the number of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	614 arguments must match. If you do want to accept any arguments, or any further
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	615 arguments, use "..._", which makes the function accept
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	616 \|vim9-variable-arguments\|. Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	617 var Callback = (..._) => 'anything'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	618 echo Callback(1, 2, 3) # displays "anything"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	619
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	620 < inline-function E1171
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	621 Additionally, a lambda can contain statements in {}: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	622 var Lambda = (arg) => {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	623 g:was_called = 'yes'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	624 return expression
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	625 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	626 This can be useful for a timer, for example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	627 var count = 0
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	628 var timer = timer_start(500, (_) => {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	629 count += 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	630 echom 'Handler called ' .. count
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	631 }, {repeat: 3})
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	632
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	633 The ending "}" must be at the start of a line. It can be followed by other
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	634 characters, e.g.: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	635 var d = mapnew(dict, (k, v): string => {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	636 return 'value'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	637 })
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	638 No command can follow the "{", only a comment can be used there.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	639
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	640 command-block E1026
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	641 The block can also be used for defining a user command. Inside the block Vim9
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	642 syntax will be used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	643
34902 d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	644 This is an example of using here-docs: >
d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	645 com SomeCommand {
d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	646 g:someVar =<< trim eval END
d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	647 ccc
d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	648 ddd
d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	649 END
d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	650 }
d1b433ed9f07 patch 9.1.0312: heredocs are not supported for :commands Christian Brabandt <cb@256bit.org> parents: 34429 diff changeset	651
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	652 If the statements include a dictionary, its closing bracket must not be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	653 written at the start of a line. Otherwise, it would be parsed as the end of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	654 the block. This does not work: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	655 command NewCommand {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	656 g:mydict = {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	657 'key': 'value',
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	658 } # ERROR: will be recognized as the end of the block
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	659 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	660 Put the '}' after the last item to avoid this: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	661 command NewCommand {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	662 g:mydict = {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	663 'key': 'value' }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	664 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	665
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	666 Rationale: The "}" cannot be after a command because it would require parsing
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	667 the commands to find it. For consistency with that no command can follow the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	668 "{". Unfortunately this means using "() => { command }" does not work, line
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	669 breaks are always required.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	670
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	671 vim9-curly
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	672 To avoid the "{" of a dictionary literal to be recognized as a statement block
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	673 wrap it in parentheses: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	674 var Lambda = (arg) => ({key: 42})
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	675
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	676 Also when confused with the start of a command block: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	677 ({
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	678 key: value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	679 })->method()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	680
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	681
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	682 Automatic line continuation ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	683 vim9-line-continuation E1097
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	684 In many cases it is obvious that an expression continues on the next line. In
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	685 those cases there is no need to prefix the line with a backslash (see
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	686 \|line-continuation\|). For example, when a list spans multiple lines: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	687 var mylist = [
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	688 'one',
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	689 'two',
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	690 ]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	691 And when a dict spans multiple lines: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	692 var mydict = {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	693 one: 1,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	694 two: 2,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	695 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	696 With a function call: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	697 var result = Func(
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	698 arg1,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	699 arg2
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	700 )
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	701
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	702 For binary operators in expressions not in [], {} or () a line break is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	703 possible just before or after the operator. For example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	704 var text = lead
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	705 .. middle
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	706 .. end
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	707 var total = start +
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	708 end -
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	709 correction
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	710 var result = positive
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	711 ? PosFunc(arg)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	712 : NegFunc(arg)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	713
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	714 For a method call using "->" and a member using a dot, a line break is allowed
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	715 before it: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	716 var result = GetBuilder()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	717 ->BuilderSetWidth(333)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	718 ->BuilderSetHeight(777)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	719 ->BuilderBuild()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	720 var result = MyDict
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	721 .member
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	722
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	723 For commands that have an argument that is a list of commands, the \| character
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	724 at the start of the line indicates line continuation: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	725 autocmd BufNewFile *.match if condition
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	726 \| echo 'match'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	727 \| endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	728
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	729 Note that this means that in heredoc the first line cannot start with a bar: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	730 var lines =<< trim END
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	731 \| this doesn't work
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	732 END
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	733 Either use an empty line at the start or do not use heredoc. Or temporarily
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	734 add the "C" flag to 'cpoptions': >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	735 set cpo+=C
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	736 var lines =<< trim END
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	737 \| this works
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	738 END
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	739 set cpo-=C
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	740 If the heredoc is inside a function 'cpoptions' must be set before :def and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	741 restored after the :enddef.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	742
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	743 In places where line continuation with a backslash is still needed, such as
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	744 splitting up a long Ex command, comments can start with '#\ ': >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	745 syn region Text
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	746 \ start='foo'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	747 #\ comment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	748 \ end='bar'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	749 Like with legacy script '"\ ' is used. This is also needed when line
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	750 continuation is used without a backslash and a line starts with a bar: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	751 au CursorHold * echom 'BEFORE bar'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	752 #\ some comment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	753 \| echom 'AFTER bar'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	754 <
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	755 E1050
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	756 To make it possible for the operator at the start of the line to be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	757 recognized, it is required to put a colon before a range. This example will
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	758 add "start" and "print": >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	759 var result = start
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	760 + print
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	761 Like this: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	762 var result = start + print
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	763
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	764 This will assign "start" and print a line: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	765 var result = start
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	766 :+ print
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	767
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	768 After the range an Ex command must follow. Without the colon you can call a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	769 function without `:call`, but after a range you do need it: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	770 MyFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	771 :% call MyFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	772
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	773 Note that the colon is not required for the \|+cmd\| argument: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	774 edit +6 fname
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	775
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	776 It is also possible to split a function header over multiple lines, in between
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	777 arguments: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	778 def MyFunc(
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	779 text: string,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	780 separator = '-'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	781 ): string
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	782
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	783 Since a continuation line cannot be easily recognized the parsing of commands
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	784 has been made stricter. E.g., because of the error in the first line, the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	785 second line is seen as a separate command: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	786 popup_create(some invalid expression, {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	787 exit_cb: Func})
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	788 Now "exit_cb: Func})" is actually a valid command: save any changes to the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	789 file "_cb: Func})" and exit. To avoid this kind of mistake in Vim9 script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	790 there must be white space between most command names and the argument.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	791 E1144
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	792
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	793 However, the argument of a command that is a command won't be recognized. For
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	794 example, after "windo echo expr" a line break inside "expr" will not be seen.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	795
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	796
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	797 Notes:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	798 - "enddef" cannot be used at the start of a continuation line, it ends the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	799 current function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	800 - No line break is allowed in the LHS of an assignment. Specifically when
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	801 unpacking a list \|:let-unpack\|. This is OK: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	802 [var1, var2] =
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	803 Func()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	804 < This does not work: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	805 [var1,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	806 var2] =
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	807 Func()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	808 - No line break is allowed in between arguments of an `:echo`, `:execute` and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	809 similar commands. This is OK: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	810 echo [1,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	811 2] [3,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	812 4]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	813 < This does not work: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	814 echo [1, 2]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	815 [3, 4]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	816 - In some cases it is difficult for Vim to parse a command, especially when
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	817 commands are used as an argument to another command, such as `:windo`. In
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	818 those cases the line continuation with a backslash has to be used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	819
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	820
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	821 White space ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	822 E1004 E1068 E1069 E1074 E1127 E1202
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	823 Vim9 script enforces proper use of white space. This is no longer allowed: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	824 var name=234 # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	825 var name= 234 # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	826 var name =234 # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	827 There must be white space before and after the "=": >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	828 var name = 234 # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	829 White space must also be put before the # that starts a comment after a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	830 command: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	831 var name = 234# Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	832 var name = 234 # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	833
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	834 White space is required around most operators.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	835
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	836 White space is required in a sublist (list slice) around the ":", except at
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	837 the start and end: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	838 otherlist = mylist[v : count] # v:count has a different meaning
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	839 otherlist = mylist[:] # make a copy of the List
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	840 otherlist = mylist[v :]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	841 otherlist = mylist[: v]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	842
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	843 White space is not allowed:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	844 - Between a function name and the "(": >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	845 Func (arg) # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	846 Func
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	847 \ (arg) # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	848 Func
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	849 (arg) # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	850 Func(arg) # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	851 Func(
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	852 arg) # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	853 Func(
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	854 arg # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	855 )
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	856 < E1205
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	857 White space is not allowed in a `:set` command between the option name and a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	858 following "&", "!", "<", "=", "+=", "-=" or "^=".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	859
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	860
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	861 No curly braces expansion ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	862
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	863 \|curly-braces-names\| cannot be used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	864
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	865
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	866 Command modifiers are not ignored ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	867 E1176
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	868 Using a command modifier for a command that does not use it gives an error.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	869 E1082
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	870 Also, using a command modifier without a following command is now an error.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	871
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	872
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	873 Dictionary literals ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	874 vim9-literal-dict E1014
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	875 Traditionally Vim has supported dictionary literals with a {} syntax: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	876 let dict = {'key': value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	877
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	878 Later it became clear that using a simple text key is very common, thus
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	879 literal dictionaries were introduced in a backwards compatible way: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	880 let dict = #{key: value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	881
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	882 However, this #{} syntax is unlike any existing language. As it turns out
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	883 that using a literal key is much more common than using an expression, and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	884 considering that JavaScript uses this syntax, using the {} form for dictionary
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	885 literals is considered a much more useful syntax. In Vim9 script the {} form
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	886 uses literal keys: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	887 var dict = {key: value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	888
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	889 This works for alphanumeric characters, underscore and dash. If you want to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	890 use another character, use a single or double quoted string: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	891 var dict = {'key with space': value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	892 var dict = {"key\twith\ttabs": value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	893 var dict = {'': value} # empty key
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	894 < E1139
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	895 In case the key needs to be an expression, square brackets can be used, just
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	896 like in JavaScript: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	897 var dict = {["key" .. nr]: value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	898
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	899 The key type can be string, number, bool or float. Other types result in an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	900 error. Without using [] the value is used as a string, keeping leading zeros.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	901 An expression given with [] is evaluated and then converted to a string.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	902 Leading zeros will then be dropped: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	903 var dict = {000123: 'without', [000456]: 'with'}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	904 echo dict
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	905 {'456': 'with', '000123': 'without'}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	906 A float only works inside [] because the dot is not accepted otherwise: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	907 var dict = {[00.013]: 'float'}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	908 echo dict
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	909 {'0.013': 'float'}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	910
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	911
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	912 No :xit, :t, :k, :append, :change or :insert ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	913 E1100
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	914 These commands are too easily confused with local variable names.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	915 Instead of `:x` or `:xit` you can use `:exit`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	916 Instead of `:t` you can use `:copy`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	917 Instead of `:k` you can use `:mark`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	918
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	919
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	920 Comparators ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	921
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	922 The 'ignorecase' option is not used for comparators that use strings.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	923 Thus "=~" works like "=~#".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	924
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	925 "is" and "isnot" (\|expr-is\| and \|expr-isnot\|) when used on strings now return
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	926 false. In legacy script they just compare the strings, in \|Vim9\| script they
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	927 check identity, and strings are copied when used, thus two strings are never
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	928 the same (this might change someday if strings are not copied but reference
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	929 counted).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	930
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	931
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	932 Abort after error ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	933
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	934 In legacy script, when an error is encountered, Vim continues to execute
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	935 following lines. This can lead to a long sequence of errors and need to type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	936 CTRL-C to stop it. In Vim9 script execution of commands stops at the first
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	937 error. Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	938 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	939 var x = does-not-exist
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	940 echo 'not executed'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	941
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	942
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	943 For loop ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	944 E1254
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	945 The loop variable must not be declared yet: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	946 var i = 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	947 for i in [1, 2, 3] # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	948
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	949 It is possible to use a global variable though: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	950 g:i = 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	951 for g:i in [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	952 echo g:i
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	953 endfor
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	954
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	955 Legacy Vim script has some tricks to make a for loop over a list handle
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	956 deleting items at the current or previous item. In Vim9 script it just uses
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	957 the index, if items are deleted then items in the list will be skipped.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	958 Example legacy script: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	959 let l = [1, 2, 3, 4]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	960 for i in l
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	961 echo i
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	962 call remove(l, index(l, i))
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	963 endfor
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	964 Would echo:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	965 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	966 2
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	967 3
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	968 4
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	969 In compiled Vim9 script you get:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	970 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	971 3
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	972 Generally, you should not change the list that is iterated over. Make a copy
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	973 first if needed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	974 When looping over a list of lists, the nested lists can be changed. The loop
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	975 variable is "final", it cannot be changed but what its value can be changed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	976 E1306
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	977 The depth of loops, :for and :while loops added together, cannot exceed 10.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	978
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	979
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	980 Conditions and expressions ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	981 vim9-boolean
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	982 Conditions and expressions are mostly working like they do in other languages.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	983 Some values are different from legacy Vim script:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	984 value legacy Vim script Vim9 script ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	985 0 falsy falsy
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	986 1 truthy truthy
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	987 99 truthy Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	988 "0" falsy Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	989 "99" truthy Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	990 "text" falsy Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	991
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	992 For the "??" operator and when using "!" then there is no error, every value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	993 is either falsy or truthy. This is mostly like JavaScript, except that an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	994 empty list and dict is falsy:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	995
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	996 type truthy when ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	997 bool true, v:true or 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	998 number non-zero
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	999 float non-zero
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1000 string non-empty
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1001 blob non-empty
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1002 list non-empty (different from JavaScript)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1003 dictionary non-empty (different from JavaScript)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1004 func when there is a function name
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1005 special true or v:true
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1006 job when not NULL
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1007 channel when not NULL
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1008 class when not NULL
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1009 object when not NULL (TODO: when isTrue() returns true)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1010
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1011 The boolean operators "\|\|" and "&&" expect the values to be boolean, zero or
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1012 one: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1013 1 \|\| false == true
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1014 0 \|\| 1 == true
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1015 0 \|\| false == false
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1016 1 && true == true
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1017 0 && 1 == false
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1018 8 \|\| 0 Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1019 'yes' && 0 Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1020 [] \|\| 99 Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1021
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1022 When using "!" for inverting, there is no error for using any type and the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1023 result is a boolean. "!!" can be used to turn any value into boolean: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1024 !'yes' == false
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1025 !![] == false
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1026 !![1, 2, 3] == true
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1027
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1028 When using "`.."` for string concatenation arguments of simple types are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1029 always converted to string: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1030 'hello ' .. 123 == 'hello 123'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1031 'hello ' .. v:true == 'hello true'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1032
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1033 Simple types are Number, Float, Special and Bool. For other types \|string()\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1034 should be used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1035 false true null null_blob null_channel
33747 23437886ecbb runtime(doc): Add missing null_<type> help tags (#13498) Christian Brabandt <cb@256bit.org> parents: 33639 diff changeset	1036 null_class null_dict null_function null_job
23437886ecbb runtime(doc): Add missing null_<type> help tags (#13498) Christian Brabandt <cb@256bit.org> parents: 33639 diff changeset	1037 null_list null_object null_partial null_string
23437886ecbb runtime(doc): Add missing null_<type> help tags (#13498) Christian Brabandt <cb@256bit.org> parents: 33639 diff changeset	1038 E1034
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1039 In Vim9 script one can use the following predefined values: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1040 true
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1041 false
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1042 null
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1043 null_blob
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1044 null_channel
32987 2129fe5a2666 runtime(todo): Update todo.txt to remove recently addressed issues (#12910) Christian Brabandt <cb@256bit.org> parents: 32670 diff changeset	1045 null_class
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1046 null_dict
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1047 null_function
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1048 null_job
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1049 null_list
32987 2129fe5a2666 runtime(todo): Update todo.txt to remove recently addressed issues (#12910) Christian Brabandt <cb@256bit.org> parents: 32670 diff changeset	1050 null_object
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1051 null_partial
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1052 null_string
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1053 `true` is the same as `v:true`, `false` the same as `v:false`, `null` the same
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1054 as `v:null`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1055
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1056 While `null` has the type "special", the other "null_" values have the type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1057 indicated by their name. Quite often a null value is handled the same as an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1058 empty value, but not always. The values can be useful to clear a script-local
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1059 variable, since they cannot be deleted with `:unlet`. E.g.: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1060 var theJob = job_start(...)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1061 # let the job do its work
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1062 theJob = null_job
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1063
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1064 The values can also be useful as the default value for an argument: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1065 def MyFunc(b: blob = null_blob)
34017 681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1066 # Note: compare against null, not null_blob,
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1067 # to distinguish the default value from an empty blob.
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1068 if b == null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1069 # b argument was not given
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1070 See \|null-compare\| for more information about testing against null.
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1071
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1072 It is possible to compare `null` with any value, this will not give a type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1073 error. However, comparing `null` with a number, float or bool will always
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1074 result in `false`. This is different from legacy script, where comparing
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1075 `null` with zero or `false` would return `true`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1076 vim9-false-true
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1077 When converting a boolean to a string `false` and `true` are used, not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1078 `v:false` and `v:true` like in legacy script. `v:none` has no `none`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1079 replacement, it has no equivalent in other languages.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1080 vim9-string-index
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1081 Indexing a string with [idx] or taking a slice with [idx : idx] uses character
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1082 indexes instead of byte indexes. Composing characters are included.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1083 Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1084 echo 'bár'[1]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1085 In legacy script this results in the character 0xc3 (an illegal byte), in Vim9
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1086 script this results in the string 'á'.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1087 A negative index is counting from the end, "[-1]" is the last character.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1088 To exclude the last character use \|slice()\|.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1089 To count composing characters separately use \|strcharpart()\|.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1090 If the index is out of range then an empty string results.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1091
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1092 In legacy script "++var" and "--var" would be silently accepted and have no
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1093 effect. This is an error in Vim9 script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1094
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1095 Numbers starting with zero are not considered to be octal, only numbers
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1096 starting with "0o" are octal: "0o744". \|scriptversion-4\|
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1097
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1098
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1099 What to watch out for ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1100 vim9-gotchas
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1101 Vim9 was designed to be closer to often used programming languages, but at the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1102 same time tries to support the legacy Vim commands. Some compromises had to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1103 be made. Here is a summary of what might be unexpected.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1104
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1105 Ex command ranges need to be prefixed with a colon. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1106 -> legacy Vim: shifts the previous line to the right
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1107 ->func() Vim9: method call in a continuation line
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1108 :-> Vim9: shifts the previous line to the right
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1109
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1110 %s/a/b legacy Vim: substitute on all lines
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1111 x = alongname
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1112 % another Vim9: modulo operator in a continuation line
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1113 :%s/a/b Vim9: substitute on all lines
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1114 't legacy Vim: jump to mark t
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1115 'text'->func() Vim9: method call
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1116 :'t Vim9: jump to mark t
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1117
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1118 Some Ex commands can be confused with assignments in Vim9 script: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1119 g:name = value # assignment
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1120 :g:pattern:cmd # :global command
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1121
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1122 To avoid confusion between a `:global` or `:substitute` command and an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1123 expression or assignment, a few separators cannot be used when these commands
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1124 are abbreviated to a single character: ':', '-' and '.'. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1125 g:pattern:cmd # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1126 s:pattern:repl # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1127 g-pattern-cmd # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1128 s-pattern-repl # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1129 g.pattern.cmd # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1130 s.pattern.repl # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1131
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1132 Also, there cannot be a space between the command and the separator: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1133 g /pattern/cmd # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1134 s /pattern/repl # invalid command - ERROR
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1135
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1136 Functions defined with `:def` compile the whole function. Legacy functions
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1137 can bail out, and the following lines are not parsed: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1138 func Maybe()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1139 if !has('feature')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1140 return
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1141 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1142 use-feature
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1143 endfunc
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1144 Vim9 functions are compiled as a whole: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1145 def Maybe()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1146 if !has('feature')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1147 return
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1148 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1149 use-feature # May give a compilation error
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1150 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1151 For a workaround, split it in two functions: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1152 func Maybe()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1153 if has('feature')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1154 call MaybeInner()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1155 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1156 endfunc
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1157 if has('feature')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1158 def MaybeInner()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1159 use-feature
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1160 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1161 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1162 Or put the unsupported code inside an `if` with a constant expression that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1163 evaluates to false: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1164 def Maybe()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1165 if has('feature')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1166 use-feature
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1167 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1168 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1169 The `exists_compiled()` function can also be used for this.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1170 vim9-user-command
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1171 Another side effect of compiling a function is that the presence of a user
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1172 command is checked at compile time. If the user command is defined later an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1173 error will result. This works: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1174 command -nargs=1 MyCommand echom <q-args>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1175 def Works()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1176 MyCommand 123
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1177 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1178 This will give an error for "MyCommand" not being defined: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1179 def Works()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1180 command -nargs=1 MyCommand echom <q-args>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1181 MyCommand 123
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1182 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1183 A workaround is to invoke the command indirectly with `:execute`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1184 def Works()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1185 command -nargs=1 MyCommand echom <q-args>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1186 execute 'MyCommand 123'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1187 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1188
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1189 Note that for unrecognized commands there is no check for "\|" and a following
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1190 command. This will give an error for missing `endif`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1191 def Maybe()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1192 if has('feature') \| use-feature \| endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1193 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1194
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1195 Other differences ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1196
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1197 Patterns are used like 'magic' is set, unless explicitly overruled.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1198 The 'edcompatible' option value is not used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1199 The 'gdefault' option value is not used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1200
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1201 You may also find this wiki useful. It was written by an early adopter of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1202 Vim9 script: https://github.com/lacygoill/wiki/blob/master/vim/vim9.md
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1203
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1204 :++ :--
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1205 The ++ and -- commands have been added. They are very similar to adding or
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1206 subtracting one: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1207 ++var
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1208 var += 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1209 --var
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1210 var -= 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1211
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1212 Using ++var or --var in an expression is not supported yet.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1213
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1214 ==============================================================================
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1215
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1216 3. New style functions fast-functions
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1217
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1218 :def E1028
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1219 :def[!] {name}([arguments])[: {return-type}]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1220 Define a new function by the name {name}. The body of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1221 the function follows in the next lines, until the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1222 matching `:enddef`. E1073
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1223 E1011
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1224 The {name} must be less than 100 bytes long.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1225 E1003 E1027 E1056 E1059
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1226 The type of value used with `:return` must match
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1227 {return-type}. When {return-type} is omitted or is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1228 "void" the function is not expected to return
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1229 anything.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1230 E1077 E1123
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1231 {arguments} is a sequence of zero or more argument
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1232 declarations. There are three forms:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1233 {name}: {type}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1234 {name} = {value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1235 {name}: {type} = {value}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1236 The first form is a mandatory argument, the caller
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1237 must always provide them.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1238 The second and third form are optional arguments.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1239 When the caller omits an argument the {value} is used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1240
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1241 The function will be compiled into instructions when
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1242 called, or when `:disassemble` or `:defcompile` is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1243 used. Syntax and type errors will be produced at that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1244 time.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1245
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1246 It is possible to nest `:def` inside another `:def` or
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1247 `:function` up to about 50 levels deep.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1248 E1117
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1249 [!] is used as with `:function`. Note that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1250 script-local functions cannot be deleted or redefined
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1251 later in Vim9 script. They can only be removed by
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1252 reloading the same script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1253
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1254 :enddef E1057 E1152 E1173
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1255 :enddef End of a function defined with `:def`. It should be on
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1256 a line by its own.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1257
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1258 You may also find this wiki useful. It was written by an early adopter of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1259 Vim9 script: https://github.com/lacygoill/wiki/blob/master/vim/vim9.md
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1260
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1261 If the script the function is defined in is Vim9 script, then script-local
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1262 variables can be accessed without the "s:" prefix. They must be defined
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1263 before the function is compiled. If the script the function is defined in is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1264 legacy script, then script-local variables must be accessed with the "s:"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1265 prefix if they do not exist at the time of compiling.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1266 E1269
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1267 Script-local variables in a \|Vim9\| script must be declared at the script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1268 level. They cannot be created in a function, also not in a legacy function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1269
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1270 :defc :defcompile
34112 0f2632b04cde patch 9.1.0020: Vim9: cannot compile all methods in a class Christian Brabandt <cb@256bit.org> parents: 34057 diff changeset	1271 :defc[ompile] Compile functions and classes (\|class-compile\|)
0f2632b04cde patch 9.1.0020: Vim9: cannot compile all methods in a class Christian Brabandt <cb@256bit.org> parents: 34057 diff changeset	1272 defined in the current script that were not compiled
0f2632b04cde patch 9.1.0020: Vim9: cannot compile all methods in a class Christian Brabandt <cb@256bit.org> parents: 34057 diff changeset	1273 yet. This will report any errors found during
0f2632b04cde patch 9.1.0020: Vim9: cannot compile all methods in a class Christian Brabandt <cb@256bit.org> parents: 34057 diff changeset	1274 compilation.
0f2632b04cde patch 9.1.0020: Vim9: cannot compile all methods in a class Christian Brabandt <cb@256bit.org> parents: 34057 diff changeset	1275
34223 89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1276 :defc[ompile] MyClass Compile all methods in a class. \|class-compile\|
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1277
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1278 :defc[ompile] {func}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1279 :defc[ompile] debug {func}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1280 :defc[ompile] profile {func}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1281 Compile function {func}, if needed. Use "debug" and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1282 "profile" to specify the compilation mode.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1283 This will report any errors found during compilation.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1284 {func} call also be "ClassName.functionName" to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1285 compile a function or method in a class.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1286 {func} call also be "ClassName" to compile all
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1287 functions and methods in a class.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1288
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1289 :disa :disassemble
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1290 :disa[ssemble] {func} Show the instructions generated for {func}.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1291 This is for debugging and testing. E1061
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1292 Note that for command line completion of {func} you
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1293 can prepend "s:" to find script-local functions.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1294
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1295 :disa[ssemble] profile {func}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1296 Like `:disassemble` but with the instructions used for
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1297 profiling.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1298
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1299 :disa[ssemble] debug {func}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1300 Like `:disassemble` but with the instructions used for
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1301 debugging.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1302
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1303 Limitations ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1304
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1305 Local variables will not be visible to string evaluation. For example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1306 def MapList(): list<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1307 var list = ['aa', 'bb', 'cc', 'dd']
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1308 return range(1, 2)->map('list[v:val]')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1309 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1310
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1311 The map argument is a string expression, which is evaluated without the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1312 function scope. Instead, use a lambda: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1313 def MapList(): list<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1314 var list = ['aa', 'bb', 'cc', 'dd']
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1315 return range(1, 2)->map((_, v) => list[v])
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1316 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1317
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1318 For commands that are not compiled, such as `:edit`, backtick expansion can be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1319 used and it can use the local scope. Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1320 def Replace()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1321 var fname = 'blah.txt'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1322 edit `=fname`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1323 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1324
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1325 Closures defined in a loop will share the same context. For example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1326 var flist: list<func>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1327 for i in range(5)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1328 var inloop = i
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1329 flist[i] = () => inloop
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1330 endfor
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1331 echo range(5)->map((i, _) => flist[i]())
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1332 # Result: [4, 4, 4, 4, 4]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1333 < E1271
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1334 A closure must be compiled in the context that it is defined in, so that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1335 variables in that context can be found. This mostly happens correctly, except
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1336 when a function is marked for debugging with `:breakadd` after it was compiled.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1337 Make sure to define the breakpoint before compiling the outer function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1338
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1339 The "inloop" variable will exist only once, all closures put in the list refer
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1340 to the same instance, which in the end will have the value 4. This is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1341 efficient, also when looping many times. If you do want a separate context
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1342 for each closure, call a function to define it: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1343 def GetClosure(i: number): func
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1344 var infunc = i
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1345 return () => infunc
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1346 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1347
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1348 var flist: list<func>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1349 for i in range(5)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1350 flist[i] = GetClosure(i)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1351 endfor
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1352 echo range(5)->map((i, _) => flist[i]())
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1353 # Result: [0, 1, 2, 3, 4]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1354
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1355 In some situations, especially when calling a Vim9 closure from legacy
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1356 context, the evaluation will fail. E1248
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1357
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1358 Note that at the script level the loop variable will be invalid after the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1359 loop, also when used in a closure that is called later, e.g. with a timer.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1360 This will generate error \|E1302\|: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1361 for n in range(4)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1362 timer_start(500 * n, (_) => {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1363 echowin n
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1364 })
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1365 endfor
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1366
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1367 You need to use a block and define a variable there, and use that one in the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1368 closure: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1369 for n in range(4)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1370 {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1371 var nr = n
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1372 timer_start(500 * n, (_) => {
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1373 echowin nr
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1374 })
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1375 }
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1376 endfor
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1377
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1378 Using `:echowindow` is useful in a timer, the messages go into a popup and will
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1379 not interfere with what the user is doing when it triggers.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1380
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1381
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1382 Converting a function from legacy to Vim9 ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1383 convert_legacy_function_to_vim9
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1384 These are the most changes that need to be made to convert a legacy function
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1385 to a Vim9 function:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1386
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1387 - Change `func` or `function` to `def`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1388 - Change `endfunc` or `endfunction` to `enddef`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1389 - Add types to the function arguments.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1390 - If the function returns something, add the return type.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1391 - Change comments to start with # instead of ".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1392
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1393 For example, a legacy function: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1394 func MyFunc(text)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1395 " function body
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1396 endfunc
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1397 < Becomes: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1398 def MyFunc(text: string): number
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1399 # function body
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1400 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1401
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1402 - Remove "a:" used for arguments. E.g.: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1403 return len(a:text)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1404 < Becomes: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1405 return len(text)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1406
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1407 - Change `let` used to declare a variable to `var`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1408 - Remove `let` used to assign a value to a variable. This is for local
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1409 variables already declared and b: w: g: and t: variables.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1410
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1411 For example, legacy function: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1412 let lnum = 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1413 let lnum += 3
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1414 let b:result = 42
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1415 < Becomes: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1416 var lnum = 1
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1417 lnum += 3
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1418 b:result = 42
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1419
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1420 - Insert white space in expressions where needed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1421 - Change "." used for concatenation to "..".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1422
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1423 For example, legacy function: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1424 echo line(1).line(2)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1425 < Becomes: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1426 echo line(1) .. line(2)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1427
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1428 - line continuation does not always require a backslash: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1429 echo ['one',
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1430 \ 'two',
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1431 \ 'three'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1432 \ ]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1433 < Becomes: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1434 echo ['one',
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1435 'two',
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1436 'three'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1437 ]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1438
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1439
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1440 Calling a function in an expr option ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1441 expr-option-function
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1442 The value of a few options, such as 'foldexpr', is an expression that is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1443 evaluated to get a value. The evaluation can have quite a bit of overhead.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1444 One way to minimize the overhead, and also to keep the option value very
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1445 simple, is to define a compiled function and set the option to call it
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1446 without arguments. Example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1447 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1448 def MyFoldFunc(): any
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1449 ... compute fold level for line v:lnum
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1450 return level
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1451 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1452 set foldexpr=s:MyFoldFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1453
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1454 ==============================================================================
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1455
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1456 4. Types vim9-types
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1457 E1008 E1009 E1010 E1012
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1458 E1013 E1029 E1030
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1459 The following builtin types are supported:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1460 bool
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1461 number
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1462 float
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1463 string
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1464 blob
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1465 list<{type}>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1466 dict<{type}>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1467 job
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1468 channel
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1469 func
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1470 func: {type}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1471 func({type}, ...)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1472 func({type}, ...): {type}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1473 void
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1474
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1475 Not supported yet:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1476 tuple<a: {type}, b: {type}, ...>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1477
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1478 These types can be used in declarations, but no simple value will actually
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1479 have the "void" type. Trying to use a void (e.g. a function without a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1480 return value) results in error E1031 E1186 .
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1481
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1482 There is no array type, use list<{type}> instead. For a list constant an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1483 efficient implementation is used that avoids allocating a lot of small pieces
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1484 of memory.
33632 2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1485 vim9-func-declaration E1005 E1007
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1486 A partial and function can be declared in more or less specific ways:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1487 func any kind of function reference, no type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1488 checking for arguments or return value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1489 func: void any number and type of arguments, no return
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1490 value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1491 func: {type} any number and type of arguments with specific
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1492 return type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1493
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1494 func() function with no argument, does not return a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1495 value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1496 func(): void same
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1497 func(): {type} function with no argument and return type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1498
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1499 func({type}) function with argument type, does not return
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1500 a value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1501 func({type}): {type} function with argument type and return type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1502 func(?{type}) function with type of optional argument, does
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1503 not return a value
33639 d6aa977fc4a9 runtime(doc): small updates to the documentation for varargs Christian Brabandt <cb@256bit.org> parents: 33632 diff changeset	1504 func(...list<{type}>) function with type of list for variable number
d6aa977fc4a9 runtime(doc): small updates to the documentation for varargs Christian Brabandt <cb@256bit.org> parents: 33632 diff changeset	1505 of arguments, does not return a value
d6aa977fc4a9 runtime(doc): small updates to the documentation for varargs Christian Brabandt <cb@256bit.org> parents: 33632 diff changeset	1506 func({type}, ?{type}, ...list<{type}>): {type}
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1507 function with:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1508 - type of mandatory argument
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1509 - type of optional argument
33639 d6aa977fc4a9 runtime(doc): small updates to the documentation for varargs Christian Brabandt <cb@256bit.org> parents: 33632 diff changeset	1510 - type of list for variable number of
d6aa977fc4a9 runtime(doc): small updates to the documentation for varargs Christian Brabandt <cb@256bit.org> parents: 33632 diff changeset	1511 arguments
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1512 - return type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1513
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1514 If the return type is "void" the function does not return a value.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1515
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1516 The reference can also be a \|Partial\|, in which case it stores extra arguments
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1517 and/or a dictionary, which are not visible to the caller. Since they are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1518 called in the same way the declaration is the same.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1519
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1520 Custom types can be defined with `:type`: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1521 :type MyList list<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1522 Custom types must start with a capital letter, to avoid name clashes with
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1523 builtin types added later, similarly to user functions.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1524
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1525 And classes and interfaces can be used as types: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1526 :class MyClass
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1527 :var mine: MyClass
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1528
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1529 :interface MyInterface
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1530 :var mine: MyInterface
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1531
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1532 :class MyTemplate<Targ>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1533 :var mine: MyTemplate<number>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1534 :var mine: MyTemplate<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1535
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1536 :class MyInterface<Targ>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1537 :var mine: MyInterface<number>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1538 :var mine: MyInterface<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1539 {not implemented yet}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1540
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1541
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1542 Variable types and type casting ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1543 variable-types
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1544 Variables declared in Vim9 script or in a `:def` function have a type, either
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1545 specified explicitly or inferred from the initialization.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1546
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1547 Global, buffer, window and tab page variables do not have a specific type, the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1548 value can be changed at any time, possibly changing the type. Therefore, in
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1549 compiled code the "any" type is assumed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1550
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1551 This can be a problem when the "any" type is undesired and the actual type is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1552 expected to always be the same. For example, when declaring a list: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1553 var l: list<number> = [1, g:two]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1554 At compile time Vim doesn't know the type of "g:two" and the expression type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1555 becomes list<any>. An instruction is generated to check the list type before
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1556 doing the assignment, which is a bit inefficient.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1557 type-casting E1104
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1558 To avoid this, use a type cast: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1559 var l: list<number> = [1, <number>g:two]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1560 The compiled code will then only check that "g:two" is a number and give an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1561 error if it isn't. This is called type casting.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1562
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1563 The syntax of a type cast is: "<" {type} ">". There cannot be white space
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1564 after the "<" or before the ">" (to avoid them being confused with
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1565 smaller-than and bigger-than operators).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1566
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1567 The semantics is that, if needed, a runtime type check is performed. The
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1568 value is not actually changed. If you need to change the type, e.g. to change
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1569 it to a string, use the \|string()\| function. Or use \|str2nr()\| to convert a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1570 string to a number.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1571
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1572 If a type is given where it is not expected you can get E1272 .
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1573
33434 484543479bd7 runtime(doc): fix typos. Christian Brabandt <cb@256bit.org> parents: 32987 diff changeset	1574 If a type is incomplete you get E1363 , e.g. when you have an object for
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1575 which the class is not known (usually that is a null object).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1576
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1577 Type inference ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1578 type-inference
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1579 In general: Whenever the type is clear it can be omitted. For example, when
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1580 declaring a variable and giving it a value: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1581 var name = 0 # infers number type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1582 var name = 'hello' # infers string type
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1583
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1584 The type of a list and dictionary comes from the common type of the values.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1585 If the values all have the same type, that type is used for the list or
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1586 dictionary. If there is a mix of types, the "any" type is used. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1587 [1, 2, 3] list<number>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1588 ['a', 'b', 'c'] list<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1589 [1, 'x', 3] list<any>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1590
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1591 The common type of function references, if they do not all have the same
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1592 number of arguments, uses "(...)" to indicate the number of arguments is not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1593 specified. For example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1594 def Foo(x: bool)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1595 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1596 def Bar(x: bool, y: bool)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1597 enddef
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1598 var funclist = [Foo, Bar]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1599 echo funclist->typename()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1600 Results in:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1601 list<func(...)>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1602
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1603 For script-local variables in Vim9 script the type is checked, also when the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1604 variable was declared in a legacy function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1605
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1606 When a type has been declared this is attached to a List or Dictionary. When
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1607 later some expression attempts to change the type an error will be given: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1608 var ll: list<number> = [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1609 ll->extend(['x']) # Error, 'x' is not a number
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1610
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1611 If the type is not declared then it is allowed to change: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1612 [1, 2, 3]->extend(['x']) # result: [1, 2, 3, 'x']
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1613
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1614 For a variable declaration an inferred type matters: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1615 var ll = [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1616 ll->extend(['x']) # Error, 'x' is not a number
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1617 That is because the declaration looks like a list of numbers, thus is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1618 equivalent to: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1619 var ll: list<number> = [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1620 If you do want a more permissive list you need to declare the type: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1621 var ll: list<any> = [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1622 ll->extend(['x']) # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1623
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1624
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1625 Stricter type checking ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1626 type-checking
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1627 In legacy Vim script, where a number was expected, a string would be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1628 automatically converted to a number. This was convenient for an actual number
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1629 such as "123", but leads to unexpected problems (and no error message) if the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1630 string doesn't start with a number. Quite often this leads to hard-to-find
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1631 bugs. e.g.: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1632 echo 123 == '123'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1633 < 1 ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1634 With an accidental space: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1635 echo 123 == ' 123'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1636 < 0 ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1637 E1206 E1210 E1212
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1638 In Vim9 script this has been made stricter. In most places it works just as
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1639 before if the value used matches the expected type. There will sometimes be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1640 an error, thus breaking backwards compatibility. For example:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1641 - Using a number other than 0 or 1 where a boolean is expected. E1023
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1642 - Using a string value when setting a number option.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1643 - Using a number where a string is expected. E1024 E1105
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1644
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1645 One consequence is that the item type of a list or dict given to \|map()\| must
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1646 not change, if the type was declared. This will give an error in Vim9
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1647 script: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1648 var mylist: list<number> = [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1649 echo map(mylist, (i, v) => 'item ' .. i)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1650 < E1012: Type mismatch; expected number but got string in map() ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1651
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1652 Instead use \|mapnew()\|, it creates a new list: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1653 var mylist: list<number> = [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1654 echo mapnew(mylist, (i, v) => 'item ' .. i)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1655 < ['item 0', 'item 1', 'item 2'] ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1656
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1657 If the item type was not declared or determined to be "any" it can change to a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1658 more specific type. E.g. when a list of mixed types gets changed to a list of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1659 strings: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1660 var mylist = [1, 2.0, '3']
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1661 # typename(mylist) == "list<any>"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1662 map(mylist, (i, v) => 'item ' .. i)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1663 # typename(mylist) == "list<string>", no error
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1664
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1665 There is a subtle difference between using a list constant directly and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1666 through a variable declaration. Because of type inference, when using a list
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1667 constant to initialize a variable, this also sets the declared type: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1668 var mylist = [1, 2, 3]
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1669 # typename(mylist) == "list<number>"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1670 echo map(mylist, (i, v) => 'item ' .. i) # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1671
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1672 When using the list constant directly, the type is not declared and is allowed
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1673 to change: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1674 echo map([1, 2, 3], (i, v) => 'item ' .. i) # OK
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1675
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1676 The reasoning behind this is that when a type is declared and the list is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1677 passed around and changed, the declaration must always hold. So that you can
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1678 rely on the type to match the declared type. For a constant this is not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1679 needed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1680
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1681 E1158
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1682 Same for \|extend()\|, use \|extendnew()\| instead, and for \|flatten()\|, use
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1683 \|flattennew()\| instead. Since \|flatten()\| is intended to always change the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1684 type, it can not be used in Vim9 script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1685
33632 2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1686 Assigning to a funcref with specified arguments (see \|vim9-func-declaration\|)
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1687 does strict type checking of the arguments. For variable number of arguments
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1688 the type must match: >
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1689 var FuncRef: func(string, number, bool): number
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1690 FuncRef = (v1: string, v2: number, v3: bool) => 777 # OK
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1691 FuncRef = (v1: string, v2: number, v3: number) => 777 # Error!
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1692 # variable number of arguments must have same type
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1693 var FuncVA: func(...list<string>): number
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1694 FuncVA = (...v: list<number>): number => v # Error!
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1695 FuncVA = (...v: list<any>): number => v # OK, `any` runtime check
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1696 FuncVA = (v1: string, v: string2): number => 333 # Error!
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1697 FuncVA = (v: list<string>): number => 3 # Error!
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1698
33902 8c4c6369239b runtime(doc): link cmdline completion to to \|wildcards\| and fix typos (#13636) Christian Brabandt <cb@256bit.org> parents: 33747 diff changeset	1699 If the destination funcref has no specified arguments, then there is no
33632 2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1700 argument type checking: >
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1701 var FuncUnknownArgs: func: number
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1702 FuncUnknownArgs = (v): number => v # OK
2c66a4fe1513 patch 9.0.2057: Vim9: no strict type checks for funcrefs varargs Christian Brabandt <cb@256bit.org> parents: 33443 diff changeset	1703 FuncUnknownArgs = (v1: string, v2: string): number => 3 # OK
33639 d6aa977fc4a9 runtime(doc): small updates to the documentation for varargs Christian Brabandt <cb@256bit.org> parents: 33632 diff changeset	1704 FuncUnknownArgs = (...v1: list<string>): number => 333 # OK
d6aa977fc4a9 runtime(doc): small updates to the documentation for varargs Christian Brabandt <cb@256bit.org> parents: 33632 diff changeset	1705 <
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1706 E1211 E1217 E1218 E1219 E1220 E1221
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1707 E1222 E1223 E1224 E1225 E1226 E1227
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1708 E1228 E1238 E1250 E1251 E1252 E1256
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1709 E1297 E1298 E1301
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1710 Types are checked for most builtin functions to make it easier to spot
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1711 mistakes.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1712
34017 681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1713 Categories of variables, defaults and null handling ~
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1714 variable-categories null-variables
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1715 There are categories of variables:
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1716 primitive number, float, boolean
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1717 container string, blob, list, dict
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1718 specialized function, job, channel, user-defined-object
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1719
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1720 When declaring a variable without an initializer, an explicit type must be
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1721 provided. Each category has different default initialization semantics. Here's
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1722 an example for each category: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1723 var num: number # primitives default to a 0 equivalent
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1724 var cont: list<string> # containers default to an empty container
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1725 var spec: job # specialized variables default to null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1726 <
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1727 Vim does not have a familiar null value; it has various null_<type> predefined
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1728 values, for example \|null_string\|, \|null_list\|, \|null_job\|. Primitives do not
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1729 have a null_<type>. The typical use cases for null_<type> are:
34223 89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1730 - to clear a variable and release its resources;
89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1731 - as a default for a parameter in a function definition, see \|null-compare\|.
34017 681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1732
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1733 For a specialized variable, like `job`, null_<type> is used to clear the
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1734 resources. For a container variable, resources can also be cleared by
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1735 assigning an empty container to the variable. For example: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1736 var j: job = job_start(...)
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1737 # ... job does its work
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1738 j = null_job # clear the variable and release the job's resources
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1739
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1740 var l: list<any>
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1741 # ... add lots of stuff to list
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1742 l = [] # clear the variable and release container resources
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1743 Using the empty container, rather than null_<type>, to clear a container
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1744 variable may avoid null complications as described in \|null-anomalies\|.
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1745
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1746 The initialization semantics of container variables and specialized variables
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1747 differ. An uninitialized container defaults to an empty container: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1748 var l1: list<string> # empty container
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1749 var l2: list<string> = [] # empty container
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1750 var l3: list<string> = null_list # null container
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1751 "l1" and "l2" are equivalent and indistinguishable initializations; but "l3"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1752 is a null container. A null container is similar to, but different from, an
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1753 empty container, see \|null-anomalies\|.
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1754
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1755 Specialized variables default to null. These job initializations are
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1756 equivalent and indistinguishable: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1757 var j1: job
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1758 var j2: job = null_job
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1759 var j3 = null_job
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1760
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1761 When a list or dict is declared, if the item type is not specified and can not
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1762 be inferred, then the type is "any": >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1763 var d1 = {} # type is "dict<any>"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1764 var d2 = null_dict # type is "dict<any>"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1765
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1766 Declaring a function, see \|vim9-func-declaration\|, is particularly unique.
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1767
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1768 null-compare
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1769 For familiar null compare semantics, where a null container is not equal to
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1770 an empty container, do not use null_<type> in a comparison: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1771 vim9script
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1772 def F(arg: list<string> = null_list)
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1773 if arg == null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1774 echo "null"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1775 else
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1776 echo printf("not null, %sempty", empty(arg) ? '' : 'not ')
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1777 endif
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1778 enddef
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1779 F() # output: "null"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1780 F(null_list) # output: "null"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1781 F([]) # output: "not null, empty"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1782 F(['']) # output: "not null, not empty"
34223 89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1783 The above function takes a list of strings and reports on it.
34017 681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1784 Change the above function signature to accept different types of arguments: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1785 def F(arg: list<any> = null_list) # any type of list
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1786 def F(arg: any = null) # any type
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1787 <
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1788 In the above example, where the goal is to distinguish a null list from an
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1789 empty list, comparing against `null` instead of `null_list` is the correct
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1790 choice. The basic reason is because "null_list == null" and "[] != null".
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1791 Comparing to `null_list` fails since "[] == null_list". In the following section
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1792 there are details about comparison results.
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1793
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1794 null-details null-anomalies
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1795 This section describes issues about using null and null_<type>; included below
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1796 are the enumerated results of null comparisons. In some cases, if familiar
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1797 with vim9 null semantics, the programmer may chose to use null_<type> in
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1798 comparisons and/or other situations.
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1799
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1800 Elsewhere in the documentation it says:
34223 89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1801 Quite often a null value is handled the same as an empty value, but
89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1802 not always
34017 681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1803 Here's an example: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1804 vim9script
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1805 var s1: list<string>
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1806 var s2: list<string> = null_list
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1807 echo s1 # output: "[]"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1808 echo s2 # output: "[]"
34223 89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1809
34017 681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1810 echo s1 + ['a'] # output: "['a']"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1811 echo s2 + ['a'] # output: "['a']"
34223 89a385d68777 runtime(doc): style fixes in vim9.txt (#13918) Christian Brabandt <cb@256bit.org> parents: 34112 diff changeset	1812
34017 681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1813 echo s1->add('a') # output: "['a']"
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1814 echo s2->add('a') # E1130: Can not add to null list
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1815 <
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1816 Two values equal to a null_<type> are not necessarily equal to each other: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1817 vim9script
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1818 echo {} == null_dict # true
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1819 echo null_dict == null # true
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1820 echo {} == null # false
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1821 <
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1822 Unlike the other containers, an uninitialized string is equal to null. The
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1823 'is' operator can be used to determine if it is a null_string: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1824 vim9script
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1825 var s1: string
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1826 var s2 = null_string
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1827 echo s1 == null # true - this is unexpected
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1828 echo s2 == null # true
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1829 echo s2 is null_string # true
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1830
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1831 var b1: blob
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1832 var b2 = null_blob
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1833 echo b1 == null # false
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1834 echo b2 == null # true
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1835 <
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1836 Any variable initialized to the null_<type> is equal to the null_<type> and is
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1837 also equal to null. For example: >
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1838 vim9script
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1839 var x = null_blob
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1840 echo x == null_blob # true
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1841 echo x == null # true
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1842 <
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1843 An uninitialized variable is usually equal to null; it depends on its type:
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1844 var s: string s == null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1845 var b: blob b != null ***
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1846 var l: list<any> l != null ***
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1847 var d: dict<any> d != null ***
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1848 var f: func f == null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1849 var j: job j == null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1850 var c: channel c == null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1851 var o: Class o == null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1852
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1853 A variable initialized to empty equals null_<type>; but not null:
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1854 var s2: string = "" == null_string != null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1855 var b2: blob = 0z == null_blob != null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1856 var l2: list<any> = [] == null_list != null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1857 var d2: dict<any> = {} == null_dict != null
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1858
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1859 NOTE: the specialized variables, like job, default to null value and have no
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1860 corresponding empty value.
681e2c008f83 runtime(doc): Add variable categories and null related documentation(#13750) Christian Brabandt <cb@256bit.org> parents: 33902 diff changeset	1861
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1862 ==============================================================================
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1863
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1864 5. Namespace, Import and Export
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1865 vim9script vim9-export vim9-import
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1866
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1867 A Vim9 script can be written to be imported. This means that some items are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1868 intentionally exported, made available to other scripts. When the exporting
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1869 script is imported in another script, these exported items can then be used in
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1870 that script. All the other items remain script-local in the exporting script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1871 and cannot be accessed by the importing script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1872
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1873 This mechanism exists for writing a script that can be sourced (imported) by
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1874 other scripts, while making sure these other scripts only have access to what
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1875 you want them to. This also avoids using the global namespace, which has a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1876 risk of name collisions. For example when you have two plugins with similar
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1877 functionality.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1878
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1879 You can cheat by using the global namespace explicitly. That should be done
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1880 only for things that really are global.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1881
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1882
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1883 Namespace ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1884 vim9-namespace
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1885 To recognize a file that can be imported the `vim9script` statement must
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1886 appear as the first statement in the file (see \|vim9-mix\| for an exception).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1887 It tells Vim to interpret the script in its own namespace, instead of the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1888 global namespace. If a file starts with: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1889 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1890 var myvar = 'yes'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1891 Then "myvar" will only exist in this file. While without `vim9script` it would
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1892 be available as `g:myvar` from any other script and function.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1893 E1101
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1894 The variables at the file level are very much like the script-local "s:"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1895 variables in legacy Vim script, but the "s:" is omitted. And they cannot be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1896 deleted.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1897
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1898 In Vim9 script the global "g:" namespace can still be used as before. And the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1899 "w:", "b:" and "t:" namespaces. These have in common that variables are not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1900 declared, have no specific type and they can be deleted. E1304
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1901
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1902 A side effect of `:vim9script` is that the 'cpoptions' option is set to the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1903 Vim default value, like with: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1904 :set cpo&vim
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1905 One of the effects is that \|line-continuation\| is always enabled.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1906 The original value of 'cpoptions' is restored at the end of the script, while
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1907 flags added or removed in the script are also added to or removed from the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1908 original value to get the same effect. The order of flags may change.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1909 In the \|vimrc\| file sourced on startup this does not happen.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1910
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1911 vim9-mix
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1912 There is one way to use both legacy and Vim9 syntax in one script file: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1913 " comments may go here
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1914 if !has('vim9script')
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1915 " legacy script commands go here
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1916 finish
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1917 endif
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1918 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1919 # Vim9 script commands go here
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1920 This allows for writing a script that takes advantage of the Vim9 script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1921 syntax if possible, but will also work on a Vim version without it.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1922
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1923 This can only work in two ways:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1924 1. The "if" statement evaluates to false, the commands up to `endif` are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1925 skipped and `vim9script` is then the first command actually executed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1926 2. The "if" statement evaluates to true, the commands up to `endif` are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1927 executed and `finish` bails out before reaching `vim9script`.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1928
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1929
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1930 Export ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1931 :export :exp
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1932 Exporting an item can be written as: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1933 export const EXPORTED_CONST = 1234
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1934 export var someValue = ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1935 export final someValue = ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1936 export const someValue = ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1937 export def MyFunc() ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1938 export class MyClass ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1939 export interface MyClass ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1940 < E1043 E1044
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1941 As this suggests, only constants, variables, `:def` functions and classes can
33434 484543479bd7 runtime(doc): fix typos. Christian Brabandt <cb@256bit.org> parents: 32987 diff changeset	1942 be exported.
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1943
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1944 E1042
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1945 `:export` can only be used in Vim9 script, at the script level.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1946
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1947
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1948 Import ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1949 :import :imp E1094 E1047 E1262
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1950 E1048 E1049 E1053 E1071 E1088 E1236
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1951 The exported items can be imported in another script. The import syntax has
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1952 two forms. The simple form: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1953 import {filename}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1954 <
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1955 Where {filename} is an expression that must evaluate to a string. In this
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1956 form the filename should end in ".vim" and the portion before ".vim" will
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1957 become the script local name of the namespace. For example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1958 import "myscript.vim"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1959 <
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1960 This makes each exported item in "myscript.vim" available as "myscript.item".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1961 :import-as E1257 E1261
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1962 In case the name is long or ambiguous, this form can be used to specify
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1963 another name: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1964 import {longfilename} as {name}
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1965 <
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1966 In this form {name} becomes a specific script local name for the imported
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1967 namespace. Therefore {name} must consist of letters, digits and '_', like
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1968 \|internal-variables\|. The {longfilename} expression must evaluate to any
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1969 filename. For example: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1970 import "thatscript.vim.v2" as that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1971 < E1060 E1258 E1259 E1260
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1972 Then you can use "that.item", etc. You are free to choose the name "that".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1973 Use something that will be recognized as referring to the imported script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1974 Avoid command names, command modifiers and builtin function names, because the
33443 6da0f8fc3046 runtime(doc): fix two typos in `vim9.txt` and `options.txt` (#13258) Christian Brabandt <cb@256bit.org> parents: 33434 diff changeset	1975 name will shadow them. It's better not to start the name with a capital
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1976 letter, since it can then also shadow global user commands and functions.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1977 Also, you cannot use the name for something else in the script, such as a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1978 function or variable name.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1979
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1980 In case the dot in the name is undesired, a local reference can be made for a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1981 function: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1982 var LongFunc = that.LongFuncName
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1983
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1984 This also works for constants: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1985 const MAXLEN = that.MAX_LEN_OF_NAME
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1986
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1987 This does not work for variables, since the value would be copied once and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1988 when changing the variable the copy will change, not the original variable.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1989 You will need to use the full name, with the dot.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1990
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1991 `:import` can not be used in a function. Imported items are intended to exist
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1992 at the script level and only imported once.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1993
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1994 The script name after `import` can be:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1995 - A relative path, starting "." or "..". This finds a file relative to the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1996 location of the script file itself. This is useful to split up a large
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1997 plugin into several files.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1998 - An absolute path, starting with "/" on Unix or "D:/" on MS-Windows. This
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	1999 will rarely be used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2000 - A path not being relative or absolute. This will be found in the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2001 "import" subdirectories of 'runtimepath' entries. The name will usually be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2002 longer and unique, to avoid loading the wrong file.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2003 Note that "after/import" is not used.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2004
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2005 If the name does not end in ".vim" then the use of "as name" is required.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2006
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2007 Once a vim9 script file has been imported, the result is cached and used the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2008 next time the same script is imported. It will not be read again.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2009
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2010 It is not allowed to import the same script twice, also when using two
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2011 different "as" names.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2012
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2013 When using the imported name the dot and the item name must be in the same
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2014 line, there can be no line break: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2015 echo that.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2016 name # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2017 echo that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2018 .name # Error!
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2019 < import-map
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2020 When you've imported a function from one script into a vim9 script you can
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2021 refer to the imported function in a mapping by prefixing it with \|<SID>\|: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2022 noremap <silent> ,a :call <SID>name.Function()<CR>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2023
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2024 When the mapping is defined "<SID>name." will be replaced with <SNR> and the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2025 script ID of the imported script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2026 An even simpler solution is using \|<ScriptCmd>\|: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2027 noremap ,a <ScriptCmd>name.Function()<CR>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2028
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2029 Note that this does not work for variables, only for functions.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2030
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2031 import-legacy legacy-import
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2032 `:import` can also be used in legacy Vim script. The imported namespace still
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2033 becomes script-local, even when the "s:" prefix is not given. For example: >
34429 a0754587f167 runtime(doc): fix inconsistent indent (#14089) Christian Brabandt <cb@256bit.org> parents: 34223 diff changeset	2034 import "myfile.vim"
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2035 call s:myfile.MyFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2036
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2037 And using the "as name" form: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2038 import "otherfile.vim9script" as that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2039 call s:that.OtherFunc()
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2040
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2041 However, the namespace cannot be resolved on its own: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2042 import "that.vim"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2043 echo s:that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2044 " ERROR: E1060: Expected dot after name: s:that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2045 <
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2046 This also affects the use of \|<SID>\| in the legacy mapping context. Since
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2047 \|<SID>\| is only a valid prefix for a function and NOT for a namespace, you
33434 484543479bd7 runtime(doc): fix typos. Christian Brabandt <cb@256bit.org> parents: 32987 diff changeset	2048 cannot use it to scope a function in a script local namespace. Instead of
484543479bd7 runtime(doc): fix typos. Christian Brabandt <cb@256bit.org> parents: 32987 diff changeset	2049 prefixing the function with \|<SID>\| you should use\|<ScriptCmd>\|. For example:
484543479bd7 runtime(doc): fix typos. Christian Brabandt <cb@256bit.org> parents: 32987 diff changeset	2050 >
32670 695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2051 noremap ,a <ScriptCmd>:call s:that.OtherFunc()<CR>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2052 <
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2053 :import-cycle
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2054 The `import` commands are executed when encountered. If script A imports
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2055 script B, and B (directly or indirectly) imports A, this will be skipped over.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2056 At this point items in A after "import B" will not have been processed and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2057 defined yet. Therefore cyclic imports can exist and not result in an error
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2058 directly, but may result in an error for items in A after "import B" not being
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2059 defined. This does not apply to autoload imports, see the next section.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2060
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2061
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2062 Importing an autoload script ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2063 vim9-autoload import-autoload
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2064 For optimal startup speed, loading scripts should be postponed until they are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2065 actually needed. Using the autoload mechanism is recommended:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2066 E1264
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2067 1. In the plugin define user commands, functions and/or mappings that refer to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2068 items imported from an autoload script. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2069 import autoload 'for/search.vim'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2070 command -nargs=1 SearchForStuff search.Stuff(<f-args>)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2071
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2072 < This goes in .../plugin/anyname.vim. "anyname.vim" can be freely chosen.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2073 The "SearchForStuff" command is now available to the user.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2074
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2075 The "autoload" argument to `:import` means that the script is not loaded
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2076 until one of the items is actually used. The script will be found under
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2077 the "autoload" directory in 'runtimepath' instead of the "import"
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2078 directory. Alternatively a relative or absolute name can be used, see
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2079 below.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2080
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2081 2. In the autoload script put the bulk of the code. >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2082 vim9script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2083 export def Stuff(arg: string)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2084 ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2085
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2086 < This goes in .../autoload/for/search.vim.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2087
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2088 Putting the "search.vim" script under the "/autoload/for/" directory has
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2089 the effect that "for#search#" will be prefixed to every exported item. The
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2090 prefix is obtained from the file name, as you would to manually in a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2091 legacy autoload script. Thus the exported function can be found with
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2092 "for#search#Stuff", but you would normally use `import autoload` and not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2093 use the prefix (which has the side effect of loading the autoload script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2094 when compiling a function that encounters this name).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2095
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2096 You can split up the functionality and import other scripts from the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2097 autoload script as you like. This way you can share code between plugins.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2098
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2099 Searching for the autoload script in all entries in 'runtimepath' can be a bit
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2100 slow. If the plugin knows where the script is located, quite often a relative
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2101 path can be used. This avoids the search and should be quite a bit faster.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2102 Another advantage is that the script name does not need to be unique. An
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2103 absolute path is also possible. Examples: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2104 import autoload '../lib/implement.vim'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2105 import autoload MyScriptsDir .. '/lib/implement.vim'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2106
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2107 For defining a mapping that uses the imported autoload script the special key
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2108 \|<ScriptCmd>\| is useful. It allows for a command in a mapping to use the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2109 script context of where the mapping was defined.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2110
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2111 When compiling a `:def` function and a function in an autoload script is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2112 encountered, the script is not loaded until the `:def` function is called.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2113 This also means you get any errors only at runtime, since the argument and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2114 return types are not known yet. If you would use the name with '#' characters
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2115 then the autoload script IS loaded.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2116
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2117 Be careful to not refer to an item in an autoload script that does trigger
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2118 loading it unintentionally. For example, when setting an option that takes a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2119 function name, make sure to use a string, not a function reference: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2120 import autoload 'qftf.vim'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2121 &quickfixtextfunc = 'qftf.Func' # autoload script NOT loaded
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2122 &quickfixtextfunc = qftf.Func # autoload script IS loaded
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2123 On the other hand, it can be useful to load the script early, at a time when
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2124 any errors should be given.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2125
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2126 For testing the \|test_override()\| function can be used to have the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2127 `import autoload` load the script right away, so that the items and types can
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2128 be checked without waiting for them to be actually used: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2129 test_override('autoload', 1)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2130 Reset it later with: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2131 test_override('autoload', 0)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2132 Or: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2133 test_override('ALL', 0)
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2134
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2135
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2136 ==============================================================================
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2137
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2138 6. Classes and interfaces vim9-classes
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2139
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2140 In legacy script a Dictionary could be used as a kind-of object, by adding
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2141 members that are functions. However, this is quite inefficient and requires
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2142 the writer to do the work of making sure all the objects have the right
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2143 members. See \|Dictionary-function\|.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2144
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2145 In \|Vim9\| script you can have classes, objects and interfaces like in most
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2146 popular object-oriented programming languages. Since this is a lot of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2147 functionality it is located in a separate help file: \|vim9class.txt\|.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2148
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2149
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2150 ==============================================================================
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2151
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2152 9. Rationale vim9-rationale
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2153
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2154 The :def command ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2155
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2156 Plugin writers have asked for much faster Vim script. Investigations have
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2157 shown that keeping the existing semantics of function calls make this close to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2158 impossible, because of the overhead involved with calling a function, setting
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2159 up the local function scope and executing lines. There are many details that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2160 need to be handled, such as error messages and exceptions. The need to create
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2161 a dictionary for a: and l: scopes, the a:000 list and several others add too
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2162 much overhead that cannot be avoided.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2163
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2164 Therefore the `:def` method to define a new-style function had to be added,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2165 which allows for a function with different semantics. Most things still work
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2166 as before, but some parts do not. A new way to define a function was
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2167 considered the best way to separate the legacy style code from Vim9 style code.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2168
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2169 Using "def" to define a function comes from Python. Other languages use
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2170 "function" which clashes with legacy Vim script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2171
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2172
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2173 Type checking ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2174
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2175 When compiling lines of Vim commands into instructions as much as possible
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2176 should be done at compile time. Postponing it to runtime makes the execution
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2177 slower and means mistakes are found only later. For example, when
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2178 encountering the "+" character and compiling this into a generic add
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2179 instruction, at runtime the instruction would have to inspect the type of the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2180 arguments and decide what kind of addition to do. And when the type is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2181 dictionary throw an error. If the types are known to be numbers then an "add
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2182 number" instruction can be used, which is faster. The error can be given at
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2183 compile time, no error handling is needed at runtime, since adding two numbers
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2184 cannot fail.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2185
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2186 The syntax for types, using <type> for compound types, is similar to Java. It
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2187 is easy to understand and widely used. The type names are what were used in
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2188 Vim before, with some additions such as "void" and "bool".
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2189
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2190
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2191 Removing clutter and weirdness ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2192
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2193 Once decided that `:def` functions have different syntax than legacy functions,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2194 we are free to add improvements to make the code more familiar for users who
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2195 know popular programming languages. In other words: remove weird things that
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2196 only Vim does.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2197
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2198 We can also remove clutter, mainly things that were done to make Vim script
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2199 backwards compatible with the good old Vi commands.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2200
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2201 Examples:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2202 - Drop `:call` for calling a function and `:eval` for evaluating an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2203 expression.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2204 - Drop using a leading backslash for line continuation, automatically figure
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2205 out where an expression ends.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2206
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2207 However, this does require that some things need to change:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2208 - Comments start with # instead of ", to avoid confusing them with strings.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2209 This is good anyway, it is also used by several popular languages.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2210 - Ex command ranges need to be prefixed with a colon, to avoid confusion with
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2211 expressions (single quote can be a string or a mark, "/" can be divide or a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2212 search command, etc.).
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2213
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2214 Goal is to limit the differences. A good criteria is that when the old syntax
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2215 is accidentally used you are very likely to get an error message.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2216
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2217
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2218 Syntax and semantics from popular languages ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2219
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2220 Script writers have complained that the Vim script syntax is unexpectedly
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2221 different from what they are used to. To reduce this complaint popular
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2222 languages are used as an example. At the same time, we do not want to abandon
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2223 the well-known parts of legacy Vim script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2224
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2225 For many things TypeScript is followed. It's a recent language that is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2226 gaining popularity and has similarities with Vim script. It also has a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2227 mix of static typing (a variable always has a known value type) and dynamic
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2228 typing (a variable can have different types, this changes at runtime). Since
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2229 legacy Vim script is dynamically typed and a lot of existing functionality
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2230 (esp. builtin functions) depends on that, while static typing allows for much
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2231 faster execution, we need to have this mix in Vim9 script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2232
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2233 There is no intention to completely match TypeScript syntax and semantics. We
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2234 just want to take those parts that we can use for Vim and we expect Vim users
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2235 will be happy with. TypeScript is a complex language with its own history,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2236 advantages and disadvantages. To get an idea of the disadvantages read the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2237 book: "JavaScript: The Good Parts". Or find the article "TypeScript: the good
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2238 parts" and read the "Things to avoid" section.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2239
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2240 People familiar with other languages (Java, Python, etc.) will also find
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2241 things in TypeScript that they do not like or do not understand. We'll try to
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2242 avoid those things.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2243
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2244 Specific items from TypeScript we avoid:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2245 - Overloading "+", using it both for addition and string concatenation. This
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2246 goes against legacy Vim script and often leads to mistakes. For that reason
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2247 we will keep using ".." for string concatenation. Lua also uses ".." this
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2248 way. And it allows for conversion to string for more values.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2249 - TypeScript can use an expression like "99 \|\| 'yes'" in a condition, but
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2250 cannot assign the value to a boolean. That is inconsistent and can be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2251 annoying. Vim recognizes an expression with && or \|\| and allows using the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2252 result as a bool. The \|falsy-operator\| was added for the mechanism to use a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2253 default value.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2254 - TypeScript considers an empty string as Falsy, but an empty list or dict as
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2255 Truthy. That is inconsistent. In Vim an empty list and dict are also
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2256 Falsy.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2257 - TypeScript has various "Readonly" types, which have limited usefulness,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2258 since a type cast can remove the immutable nature. Vim locks the value,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2259 which is more flexible, but is only checked at runtime.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2260 - TypeScript has a complicated "import" statement that does not match how the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2261 Vim import mechanism works. A much simpler mechanism is used instead, which
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2262 matches that the imported script is only sourced once.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2263
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2264
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2265 Declarations ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2266
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2267 Legacy Vim script uses `:let` for every assignment, while in Vim9 declarations
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2268 are used. That is different, thus it's good to use a different command:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2269 `:var`. This is used in many languages. The semantics might be slightly
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2270 different, but it's easily recognized as a declaration.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2271
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2272 Using `:const` for constants is common, but the semantics varies. Some
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2273 languages only make the variable immutable, others also make the value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2274 immutable. Since "final" is well known from Java for only making the variable
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2275 immutable we decided to use that. And then `:const` can be used for making
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2276 both immutable. This was also used in legacy Vim script and the meaning is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2277 almost the same.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2278
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2279 What we end up with is very similar to Dart: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2280 :var name # mutable variable and value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2281 :final name # immutable variable, mutable value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2282 :const name # immutable variable and value
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2283
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2284 Since legacy and Vim9 script will be mixed and global variables will be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2285 shared, optional type checking is desirable. Also, type inference will avoid
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2286 the need for specifying the type in many cases. The TypeScript syntax fits
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2287 best for adding types to declarations: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2288 var name: string # string type is specified
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2289 ...
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2290 name = 'John'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2291 const greeting = 'hello' # string type is inferred
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2292
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2293 This is how we put types in a declaration: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2294 var mylist: list<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2295 final mylist: list<string> = ['foo']
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2296 def Func(arg1: number, arg2: string): bool
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2297
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2298 Two alternatives were considered:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2299 1. Put the type before the name, like Dart: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2300 var list<string> mylist
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2301 final list<string> mylist = ['foo']
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2302 def Func(number arg1, string arg2) bool
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2303 2. Put the type after the variable name, but do not use a colon, like Go: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2304 var mylist list<string>
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2305 final mylist list<string> = ['foo']
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2306 def Func(arg1 number, arg2 string) bool
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2307
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2308 The first is more familiar for anyone used to C or Java. The second one
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2309 doesn't really have an advantage over the first, so let's discard the second.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2310
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2311 Since we use type inference the type can be left out when it can be inferred
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2312 from the value. This means that after `var` we don't know if a type or a name
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2313 follows. That makes parsing harder, not only for Vim but also for humans.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2314 Also, it will not be allowed to use a variable name that could be a type name,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2315 using `var string string` is too confusing.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2316
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2317 The chosen syntax, using a colon to separate the name from the type, adds
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2318 punctuation, but it actually makes it easier to recognize the parts of a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2319 declaration.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2320
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2321
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2322 Expressions ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2323
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2324 Expression evaluation was already close to what other languages are doing.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2325 Some details are unexpected and can be improved. For example a boolean
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2326 condition would accept a string, convert it to a number and check if the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2327 number is non-zero. This is unexpected and often leads to mistakes, since
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2328 text not starting with a number would be converted to zero, which is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2329 considered false. Thus using a string for a condition would often not give an
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2330 error and be considered false. That is confusing.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2331
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2332 In Vim9 type checking is stricter to avoid mistakes. Where a condition is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2333 used, e.g. with the `:if` command and the `\|\|` operator, only boolean-like
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2334 values are accepted:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2335 true: `true`, `v:true`, `1`, `0 < 9`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2336 false: `false`, `v:false`, `0`, `0 > 9`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2337 Note that the number zero is false and the number one is true. This is more
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2338 permissive than most other languages. It was done because many builtin
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2339 functions return these values, and changing that causes more problems than it
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2340 solves. After using this for a while it turned out to work well.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2341
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2342 If you have any type of value and want to use it as a boolean, use the `!!`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2343 operator:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2344 true: `!!'text'` `!![99]` `!!{'x': 1}` `!!99`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2345 false: `!!''` `!![]` `!!{}`
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2346
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2347 From a language like JavaScript we have this handy construct: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2348 GetName() \|\| 'unknown'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2349 However, this conflicts with only allowing a boolean for a condition.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2350 Therefore the "??" operator was added: >
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2351 GetName() ?? 'unknown'
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2352 Here you can explicitly express your intention to use the value as-is and not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2353 result in a boolean. This is called the \|falsy-operator\|.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2354
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2355
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2356 Import and Export ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2357
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2358 A problem of legacy Vim script is that by default all functions and variables
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2359 are global. It is possible to make them script-local, but then they are not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2360 available in other scripts. This defies the concept of a package that only
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2361 exports selected items and keeps the rest local.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2362
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2363 In Vim9 script a mechanism very similar to the JavaScript import and export
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2364 mechanism is supported. It is a variant to the existing `:source` command
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2365 that works like one would expect:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2366 - Instead of making everything global by default, everything is script-local,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2367 some of these are exported.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2368 - When importing a script the symbols that are imported are explicitly listed,
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2369 avoiding name conflicts and failures if functionality is added later.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2370 - The mechanism allows for writing a big, long script with a very clear API:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2371 the exported functions, variables and classes.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2372 - By using relative paths loading can be much faster for an import inside of a
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2373 package, no need to search many directories.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2374 - Once an import has been used, its items are cached and loading it again is
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2375 not needed.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2376 - The Vim-specific use of "s:" to make things script-local can be dropped.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2377
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2378 When sourcing a Vim9 script (from a Vim9 or legacy script), only the items
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2379 defined globally can be used, not the exported items. Alternatives
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2380 considered:
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2381 - All the exported items become available as script-local items. This makes
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2382 it uncontrollable what items get defined and likely soon leads to trouble.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2383 - Use the exported items and make them global. Disadvantage is that it's then
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2384 not possible to avoid name clashes in the global namespace.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2385 - Completely disallow sourcing a Vim9 script, require using `:import`. That
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2386 makes it difficult to use scripts for testing, or sourcing them from the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2387 command line to try them out.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2388 Note that you CAN also use `:import` in legacy Vim script, see above.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2389
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2390
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2391 Compiling functions early ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2392
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2393 Functions are compiled when called or when `:defcompile` is used. Why not
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2394 compile them early, so that syntax and type errors are reported early?
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2395
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2396 The functions can't be compiled right away when encountered, because there may
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2397 be forward references to functions defined later. Consider defining functions
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2398 A, B and C, where A calls B, B calls C, and C calls A again. It's impossible
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2399 to reorder the functions to avoid forward references.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2400
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2401 An alternative would be to first scan through the file to locate items and
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2402 figure out their type, so that forward references are found, and only then
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2403 execute the script and compile the functions. This means the script has to be
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2404 parsed twice, which is slower, and some conditions at the script level, such
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2405 as checking if a feature is supported, are hard to use. An attempt was made
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2406 to see if it works, but it turned out to be impossible to make work well.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2407
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2408 It would be possible to compile all the functions at the end of the script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2409 The drawback is that if a function never gets called, the overhead of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2410 compiling it counts anyway. Since startup speed is very important, in most
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2411 cases it's better to do it later and accept that syntax and type errors are
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2412 only reported then. In case these errors should be found early, e.g. when
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2413 testing, a `:defcompile` command at the end of the script will help out.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2414
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2415
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2416 Why not use an existing embedded language? ~
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2417
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2418 Vim supports interfaces to Perl, Python, Lua, Tcl and a few others. But
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2419 these interfaces have never become widely used, for various reasons. When
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2420 Vim9 was designed a decision was made to make these interfaces lower priority
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2421 and concentrate on Vim script.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2422
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2423 Still, plugin writers may find other languages more familiar, want to use
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2424 existing libraries or see a performance benefit. We encourage plugin authors
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2425 to write code in any language and run it as an external process, using jobs
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2426 and channels. We can try to make this easier somehow.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2427
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2428 Using an external tool also has disadvantages. An alternative is to convert
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2429 the tool into Vim script. For that to be possible without too much
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2430 translation, and keeping the code fast at the same time, the constructs of the
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2431 tool need to be supported. Since most languages support classes the lack of
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2432 support for classes in Vim is then a problem.
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2433
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2434
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2435
695b50472e85 Fix line endings issue Christian Brabandt <cb@256bit.org> parents: 32669 diff changeset	2436 vim:tw=78:ts=8:noet:ft=help:norl:

Mercurial > vim

annotate runtime/doc/vim9.txt @ 35145:8b9f22608aa5 default tip