vim: runtime/doc/vim9.txt annotate

annotate runtime/doc/vim9.txt @ 23318:c76240efdf02 v8.2.2204

patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Commit: https://github.com/vim/vim/commit/65c4415276394c871c7a8711c7633c19ec9235b1 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Dec 24 15:14:01 2020 +0100 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Problem: Vim9: using -> both for method and lambda is confusing. Solution: Use => for lambda in :def function.

author	Bram Moolenaar <Bram@vim.org>
date	Thu, 24 Dec 2020 15:15:05 +0100
parents	fab58304f77d
children	b3142fc0a414

rev	line source
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	1 vim9.txt For Vim version 8.2. Last change: 2020 Dec 24
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	2
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	3
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	4 VIM REFERENCE MANUAL by Bram Moolenaar
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	5
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	6
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	7 THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	8
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	9 Vim9 script commands and expressions. Vim9
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	10
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	11 Most expression help is in \|eval.txt\|. This file is about the new syntax and
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	12 features in Vim9 script.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	13
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	14 THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	15
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	16
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	17 1. What is Vim9 script? \|vim9-script\|
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	18 2. Differences \|vim9-differences\|
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	19 3. New style functions \|fast-functions\|
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	20 4. Types \|vim9-types\|
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	21 5. Namespace, Import and Export \|vim9script\|
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	22 6. Future work: classes \|vim9-classes\|
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	23
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	24 9. Rationale \|vim9-rationale\|
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	25
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	26 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	27
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	28 1. What is Vim9 script? vim9-script
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	29
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	30 THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	31
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	32 Vim script has been growing over time, while preserving backwards
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	33 compatibility. That means bad choices from the past often can't be changed
20965 59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	34 and compatibility with Vi restricts possible solutions. Execution is quite
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	35 slow, each line is parsed every time it is executed.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	36
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	37 The main goal of Vim9 script is to drastically improve performance. This is
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	38 accomplished by compiling commands into instructions that can be efficiently
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	39 executed. An increase in execution speed of 10 to 100 times can be expected.
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	40
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	41 A secondary goal is to avoid Vim-specific constructs and get closer to
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	42 commonly used programming languages, such as JavaScript, TypeScript and Java.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	43
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	44 The performance improvements can only be achieved by not being 100% backwards
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	45 compatible. For example, making function arguments available in the
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	46 "a:" dictionary adds quite a lot of overhead. In a Vim9 function this
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	47 dictionary is not available. Other differences are more subtle, such as how
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	48 errors are handled.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	49
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	50 The Vim9 script syntax and semantics are used in:
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	51 - a function defined with the `:def` command
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	52 - a script file where the first command is `vim9script`
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	53 - an autocommand defined in the context of the above
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	54
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	55 When using `:function` in a Vim9 script file the legacy syntax is used.
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	56 However, this can be confusing and is therefore discouraged.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	57
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	58 Vim9 script and legacy Vim script can be mixed. There is no requirement to
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	59 rewrite old scripts, they keep working as before. You may want to use a few
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	60 `:def` functions for code that needs to be fast.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	61
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	62 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	63
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	64 2. Differences from legacy Vim script vim9-differences
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	65
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	66 THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	67
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	68 Overview ~
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	69
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	70 Brief summary of the differences you will most often encounter when using Vim9
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	71 script and `:def` functions; details are below:
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	72 - Comments start with #, not ": >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	73 echo "hello" # comment
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	74 - Using a backslash for line continuation is hardly ever needed: >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	75 echo "hello "
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	76 .. yourName
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	77 .. ", how are you?"
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	78 - White space is required in many places.
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	79 - Assign values without `:let`, declare variables with `:var`: >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	80 var count = 0
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	81 count += 3
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	82 - Constants can be declared with `:final` and `:const`: >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	83 final matches = [] # add matches
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	84 const names = ['Betty', 'Peter'] # cannot be changed
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	85 - `:final` cannot be used as an abbreviation of `:finally`.
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	86 - Variables and functions are script-local by default.
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	87 - Functions are declared with argument types and return type: >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	88 def CallMe(count: number, message: string): bool
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	89 - Call functions without `:call`: >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	90 writefile(['done'], 'file.txt')
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	91 - You cannot use `:xit`, `:t`, `:append`, `:change`, `:insert` or curly-braces
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	92 names.
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	93 - A range before a command must be prefixed with a colon: >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	94 :%s/this/that
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	95
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	96
20023 c85d4e173cc9 patch 8.2.0567: Vim9: cannot put comments halfway expressions Bram Moolenaar <Bram@vim.org> parents: 20015 diff changeset	97 Comments starting with # ~
c85d4e173cc9 patch 8.2.0567: Vim9: cannot put comments halfway expressions Bram Moolenaar <Bram@vim.org> parents: 20015 diff changeset	98
21353 fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	99 In legacy Vim script comments start with double quote. In Vim9 script
fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	100 comments start with #. >
fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	101 # declarations
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	102 var count = 0 # number of occurrences
20023 c85d4e173cc9 patch 8.2.0567: Vim9: cannot put comments halfway expressions Bram Moolenaar <Bram@vim.org> parents: 20015 diff changeset	103
21353 fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	104 The reason is that a double quote can also be the start of a string. In many
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	105 places, especially halfway through an expression with a line break, it's hard
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	106 to tell what the meaning is, since both a string and a comment can be followed
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	107 by arbitrary text. To avoid confusion only # comments are recognized. This
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	108 is the same as in shell scripts and Python programs.
21353 fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	109
fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	110 In Vi # is a command to list text with numbers. In Vim9 script you can use
fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	111 `:number` for that. >
21516 c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	112 101 number
21353 fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	113
fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	114 To improve readability there must be a space between a command and the #
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	115 that starts a comment.
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	116
20023 c85d4e173cc9 patch 8.2.0567: Vim9: cannot put comments halfway expressions Bram Moolenaar <Bram@vim.org> parents: 20015 diff changeset	117
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	118 Vim9 functions ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	119
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	120 A function defined with `:def` is compiled. Execution is many times faster,
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	121 often 10x to 100x times.
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	122
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	123 Many errors are already found when compiling, before the function is executed.
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	124 The syntax is strict, to enforce code that is easy to read and understand.
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	125
23164 99ef85ff1af4 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23088 diff changeset	126 Compilation is done when either of these is encountered:
99ef85ff1af4 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23088 diff changeset	127 - the first time the function is called
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	128 - when the `:defcompile` command is encountered in the script where the
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	129 function was defined
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	130 - `:disassemble` is used for the function.
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	131 - a function that is compiled calls the function or uses it as a function
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	132 reference
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	133
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	134 `:def` has no options like `:function` does: "range", "abort", "dict" or
23164 99ef85ff1af4 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23088 diff changeset	135 "closure". A `:def` function always aborts on an error (unless `:silent!` was
99ef85ff1af4 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23088 diff changeset	136 used for the command or inside a `:try` block), does not get a range passed
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	137 cannot be a "dict" function, and can always be a closure.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	138
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	139 The argument types and return type need to be specified. The "any" type can
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	140 be used, type checking will then be done at runtime, like with legacy
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	141 functions.
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	142
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	143 Arguments are accessed by name, without "a:", just like any other language.
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	144 There is no "a:" dictionary or "a:000" list.
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	145
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	146 Variable arguments are defined as the last argument, with a name and have a
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	147 list type, similar to TypeScript. For example, a list of numbers: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	148 def MyFunc(...itemlist: list<number>)
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	149 for item in itemlist
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	150 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	151
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	152
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	153 Functions and variables are script-local by default ~
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	154 vim9-scopes
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	155 When using `:function` or `:def` to specify a new function at the script level
bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	156 in a Vim9 script, the function is local to the script, as if "s:" was
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	157 prefixed. Using the "s:" prefix is optional. To define a global function or
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	158 variable the "g:" prefix must be used. For functions in an autoload script
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	159 the "name#" prefix is sufficient. >
21550 b0b57d91671c patch 8.2.1325: Vim9: using Vim9 script for autaload not tested Bram Moolenaar <Bram@vim.org> parents: 21516 diff changeset	160 def ThisFunction() # script-local
b0b57d91671c patch 8.2.1325: Vim9: using Vim9 script for autaload not tested Bram Moolenaar <Bram@vim.org> parents: 21516 diff changeset	161 def s:ThisFunction() # script-local
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	162 def g:ThatFunction() # global
21550 b0b57d91671c patch 8.2.1325: Vim9: using Vim9 script for autaload not tested Bram Moolenaar <Bram@vim.org> parents: 21516 diff changeset	163 def scriptname#function() # autoload
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	164
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	165 When using `:function` or `:def` to specify a nested function inside a `:def`
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	166 function, this nested function is local to the code block it is defined in.
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	167 In a `:def` function it is not possible to define a script-local function. It
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	168 is possible to define a global function by using the "g:" prefix.
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	169
bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	170 When referring to a function and no "s:" or "g:" prefix is used, Vim will
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	171 search for the function:
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	172 - in the function scope, in block scopes
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	173 - in the script scope, possibly imported
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	174 - in the list of global functions
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	175 However, it is recommended to always use "g:" to refer to a global function
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	176 for clarity.
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	177
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	178 In all cases the function must be defined before used. That is when it is
22723 5b7ea82bc18f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22565 diff changeset	179 called, when `:defcompile` causes it to be compiled, or when code that calls
5b7ea82bc18f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22565 diff changeset	180 it is being compiled (to figure out the return type).
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	181
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	182 The result is that functions and variables without a namespace can usually be
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	183 found in the script, either defined there or imported. Global functions and
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	184 variables could be defined anywhere (good luck finding out where!).
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	185
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	186 Global functions can still be defined and deleted at nearly any time. In
20317 2334bf788e8a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20241 diff changeset	187 Vim9 script script-local functions are defined once when the script is sourced
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	188 and cannot be deleted or replaced.
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	189
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	190 When compiling a function and a function call is encountered for a function
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	191 that is not (yet) defined, the \|FuncUndefined\| autocommand is not triggered.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	192 You can use an autoload function if needed, or call a legacy function and have
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	193 \|FuncUndefined\| triggered there.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	194
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	195
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	196 Variable declarations with :var, :final and :const ~
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	197 vim9-declaration :var
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	198 Local variables need to be declared with `:var`. Local constants need to be
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	199 declared with `:final` or `:const`. We refer to both as "variables" in this
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	200 section.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	201
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	202 Variables can be local to a script, function or code block: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	203 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	204 var script_var = 123
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	205 def SomeFunc()
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	206 var func_var = script_var
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	207 if cond
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	208 var block_var = func_var
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	209 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	210
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	211 The variables are only visible in the block where they are defined and nested
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	212 blocks. Once the block ends the variable is no longer accessible: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	213 if cond
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	214 var inner = 5
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	215 else
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	216 var inner = 0
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	217 endif
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	218 echo inner # Error!
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	219
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	220 The declaration must be done earlier: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	221 var inner: number
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	222 if cond
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	223 inner = 5
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	224 else
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	225 inner = 0
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	226 endif
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	227 echo inner
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	228
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	229 To intentionally hide a variable from code that follows, a block can be
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	230 used: >
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	231 {
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	232 var temp = 'temp'
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	233 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	234 }
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	235 echo temp # Error!
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	236
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	237 Declaring a variable with a type but without an initializer will initialize to
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	238 zero, false or empty.
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	239
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	240 In Vim9 script `:let` cannot be used. An existing variable is assigned to
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	241 without any command. The same for global, window, tab, buffer and Vim
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	242 variables, because they are not really declared. They can also be deleted
21584 d0c76ce48326 patch 8.2.1342: Vim9: accidentally using "t" gives a confusing error Bram Moolenaar <Bram@vim.org> parents: 21550 diff changeset	243 with `:unlet`.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	244
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	245 Variables and functions cannot shadow previously defined or imported variables
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	246 and functions.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	247 Variables may shadow Ex commands, rename the variable if needed.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	248
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	249 Global variables and user defined functions must be prefixed with "g:", also
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	250 at the script level. >
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	251 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	252 var script_local = 'text'
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	253 g:global = 'value'
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	254 var Funcref = g:ThatFunction
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	255
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	256 Since `&opt = value` is now assigning a value to option "opt", ":&" cannot be
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	257 used to repeat a `:substitute` command.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	258
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	259
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	260 Constants ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	261 vim9-const vim9-final
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	262 How constants work varies between languages. Some consider a variable that
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	263 can't be assigned another value a constant. JavaScript is an example. Others
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	264 also make the value immutable, thus when a constant uses a list, the list
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	265 cannot be changed. In Vim9 we can use both.
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	266
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	267 `:const` is used for making both the variable and the value a constant. Use
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	268 this for composite structures that you want to make sure will not be modified.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	269 Example: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	270 const myList = [1, 2]
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	271 myList = [3, 4] # Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	272 myList[0] = 9 # Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	273 muList->add(3) # Error!
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	274 < :final
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	275 `:final` is used for making only the variable a constant, the value can be
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	276 changed. This is well known from Java. Example: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	277 final myList = [1, 2]
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	278 myList = [3, 4] # Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	279 myList[0] = 9 # OK
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	280 muList->add(3) # OK
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	281
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	282 It is common to write constants as ALL_CAPS, but you don't have to.
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	283
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	284 The constant only applies to the value itself, not what it refers to. >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	285 final females = ["Mary"]
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	286 const NAMES = [["John", "Peter"], females]
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	287 NAMES[0] = ["Jack"] # Error!
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	288 NAMES[0][0] = "Jack" # Error!
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	289 NAMES[1] = ["Emma"] # Error!
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	290 Names[1][0] = "Emma" # OK, now females[0] == "Emma"
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	291
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	292 < E1092
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	293 Declaring more than one variable at a time, using the unpack notation, is
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	294 currently not supported: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	295 var [v1, v2] = GetValues() # Error!
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	296 That is because the type needs to be inferred from the list item type, which
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	297 isn't that easy.
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	298
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	299
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	300 Omitting :call and :eval ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	301
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	302 Functions can be called without `:call`: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	303 writefile(lines, 'file')
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	304 Using `:call` is still possible, but this is discouraged.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	305
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	306 A method call without `eval` is possible, so long as the start is an
21516 c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	307 identifier or can't be an Ex command. Examples: >
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	308 myList->add(123)
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	309 g:myList->add(123)
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	310 [1, 2, 3]->Process()
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	311 {a: 1, b: 2}->Process()
21516 c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	312 "foobar"->Process()
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	313 ("foobar")->Process()
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	314 'foobar'->Process()
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	315 ('foobar')->Process()
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	316
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	317 In the rare case there is ambiguity between a function name and an Ex command,
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	318 prepend ":" to make clear you want to use the Ex command. For example, there
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	319 is both the `:substitute` command and the `substitute()` function. When the
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	320 line starts with `substitute(` this will use the function. Prepend a colon to
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	321 use the command instead: >
19481 c27837cbe922 patch 8.2.0298: Vim9 script: cannot start command with a string constant Bram Moolenaar <Bram@vim.org> parents: 19473 diff changeset	322 :substitute(pattern (replacement (
19473 b09afbebffee patch 8.2.0294: cannot use Ex command that is also a function name Bram Moolenaar <Bram@vim.org> parents: 19404 diff changeset	323
19556 ff5048b0ccfe patch 8.2.0335: no completion for :disassemble Bram Moolenaar <Bram@vim.org> parents: 19523 diff changeset	324 Note that while variables need to be defined before they can be used,
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	325 functions can be called before being defined. This is required to allow
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	326 for cyclic dependencies between functions. It is slightly less efficient,
19556 ff5048b0ccfe patch 8.2.0335: no completion for :disassemble Bram Moolenaar <Bram@vim.org> parents: 19523 diff changeset	327 since the function has to be looked up by name. And a typo in the function
21516 c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	328 name will only be found when the function is called.
19556 ff5048b0ccfe patch 8.2.0335: no completion for :disassemble Bram Moolenaar <Bram@vim.org> parents: 19523 diff changeset	329
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	330
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	331 Omitting function() ~
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	332
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	333 A user defined function can be used as a function reference in an expression
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	334 without `function()`. The argument types and return type will then be checked.
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	335 The function must already have been defined. >
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	336
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	337 var Funcref = MyFunction
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	338
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	339 When using `function()` the resulting type is "func", a function with any
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	340 number of arguments and any return type. The function can be defined later.
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	341
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	342
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	343 Lamba using => instead of -> ~
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	344
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	345 In legacy script there can be confusion between using "->" for a method call
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	346 and for a lambda. Also, when a "{" is found the parser needs to figure out if
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	347 it is the start of a lambda or a dictionary, which is now more complicated
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	348 because of the use of argument types.
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	349
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	350 To avoid these problems Vim9 script uses a different syntax for a lambda,
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	351 which is similar to Javascript: >
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	352 var Lambda = (arg) => expression
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	353
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	354 No line break is allowed in the arguments of a lambda up to and includeing the
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	355 "=>". This is OK: >
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	356 filter(list, (k, v) =>
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	357 v > 0)
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	358 This does not work: >
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	359 filter(list, (k, v)
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	360 => v > 0)
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	361 This also does not work:
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	362 filter(list, (k,
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	363 v) => v > 0)
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	364
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	365 Additionally, a lambda can contain statements in {}: >
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	366 var Lambda = (arg) => {
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	367 g:was_called = 'yes'
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	368 return expression
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	369 }
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	370 NOT IMPLEMENTED YET
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	371
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	372 Note that the "{" must be followed by white space, otherwise it is assumed to
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	373 be the start of a dictionary: >
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	374 var Lambda = (arg) => {key: 42}
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	375
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	376
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	377 Automatic line continuation ~
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	378
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	379 In many cases it is obvious that an expression continues on the next line. In
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	380 those cases there is no need to prefix the line with a backslash
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	381 \|line-continuation\|. For example, when a list spans multiple lines: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	382 var mylist = [
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	383 'one',
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	384 'two',
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	385 ]
20011 628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	386 And when a dict spans multiple lines: >
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	387 var mydict = {
20011 628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	388 one: 1,
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	389 two: 2,
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	390 }
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	391 Function call: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	392 var result = Func(
20011 628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	393 arg1,
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	394 arg2
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	395 )
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	396
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	397 For binary operators in expressions not in [], {} or () a line break is
bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	398 possible just before or after the operator. For example: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	399 var text = lead
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	400 .. middle
bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	401 .. end
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	402 var total = start +
20013 bf377a9ffccb patch 8.2.0562: Vim9: cannot split an expression into multiple lines Bram Moolenaar <Bram@vim.org> parents: 20011 diff changeset	403 end -
bf377a9ffccb patch 8.2.0562: Vim9: cannot split an expression into multiple lines Bram Moolenaar <Bram@vim.org> parents: 20011 diff changeset	404 correction
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	405 var result = positive
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	406 ? PosFunc(arg)
bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	407 : NegFunc(arg)
20013 bf377a9ffccb patch 8.2.0562: Vim9: cannot split an expression into multiple lines Bram Moolenaar <Bram@vim.org> parents: 20011 diff changeset	408
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	409 For a method call using "->" and a member using a dot, a line break is allowed
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	410 before it: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	411 var result = GetBuilder()
20965 59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	412 ->BuilderSetWidth(333)
59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	413 ->BuilderSetHeight(777)
59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	414 ->BuilderBuild()
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	415 var result = MyDict
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	416 .member
20965 59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	417
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	418 < E1050
bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	419 To make it possible for the operator at the start of the line to be
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	420 recognized, it is required to put a colon before a range. This will add
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	421 "start" and print: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	422 var result = start
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	423 + print
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	424 Like this: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	425 var result = start + print
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	426
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	427 This will assign "start" and print a line: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	428 var result = start
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	429 :+ print
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	430
23047 29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	431 Note that the colon is not required for the \|+cmd\| argument: >
29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	432 edit +6 fname
29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	433
20015 c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	434 It is also possible to split a function header over multiple lines, in between
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	435 arguments: >
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	436 def MyFunc(
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	437 text: string,
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	438 separator = '-'
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	439 ): string
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	440
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	441 Since a continuation line cannot be easily recognized the parsing of commands
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	442 has been made stricter. E.g., because of the error in the first line, the
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	443 second line is seen as a separate command: >
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	444 popup_create(some invalid expression, {
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	445 exit_cb: Func})
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	446 Now "exit_cb: Func})" is actually a valid command: save any changes to the
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	447 file "_cb: Func})" and exit. To avoid this kind of mistake in Vim9 script
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	448 there must be white space between most command names and the argument.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	449
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	450
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	451 Notes:
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	452 - "enddef" cannot be used at the start of a continuation line, it ends the
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	453 current function.
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	454 - No line break is allowed in the LHS of an assignment. Specifically when
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	455 unpacking a list \|:let-unpack\|. This is OK: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	456 [var1, var2] =
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	457 Func()
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	458 < This does not work: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	459 [var1,
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	460 var2] =
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	461 Func()
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	462 - No line break is allowed in between arguments of an `:echo`, `:execute` and
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	463 similar commands. This is OK: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	464 echo [1,
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	465 2] [3,
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	466 4]
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	467 < This does not work: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	468 echo [1, 2]
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	469 [3, 4]
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	470
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	471 No curly braces expansion ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	472
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	473 \|curly-braces-names\| cannot be used.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	474
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	475
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	476 Dictionary literals ~
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	477
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	478 Traditionally Vim has supported dictionary literals with a {} syntax: >
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	479 let dict = {'key': value}
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	480
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	481 Later it became clear that using a simple text key is very common, thus
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	482 literal dictionaries were introduced in a backwards compatible way: >
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	483 let dict = #{key: value}
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	484
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	485 However, this #{} syntax is unlike any existing language. As it turns out
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	486 that using a literal key is much more common than using an expression, and
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	487 considering that JavaScript uses this syntax, using the {} form for dictionary
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	488 literals is considered a much more useful syntax. In Vim9 script the {} form
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	489 uses literal keys: >
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	490 let dict = {key: value}
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	491
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	492 This works for alphanumeric characters, underscore and dash. If you want to
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	493 use another character, use a single or double quoted string: >
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	494 let dict = {'key with space': value}
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	495 let dict = {"key\twith\ttabs": value}
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	496 let dict = {'': value} # empty key
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	497
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	498 In case the key needs to be an expression, square brackets can be used, just
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	499 like in JavaScript: >
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	500 let dict = {["key" .. nr]: value}
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	501
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	502
21584 d0c76ce48326 patch 8.2.1342: Vim9: accidentally using "t" gives a confusing error Bram Moolenaar <Bram@vim.org> parents: 21550 diff changeset	503 No :xit, :t, :append, :change or :insert ~
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	504
21584 d0c76ce48326 patch 8.2.1342: Vim9: accidentally using "t" gives a confusing error Bram Moolenaar <Bram@vim.org> parents: 21550 diff changeset	505 These commands are too easily confused with local variable names.
d0c76ce48326 patch 8.2.1342: Vim9: accidentally using "t" gives a confusing error Bram Moolenaar <Bram@vim.org> parents: 21550 diff changeset	506 Instead of `:x` or `:xit` you can use `:exit`.
d0c76ce48326 patch 8.2.1342: Vim9: accidentally using "t" gives a confusing error Bram Moolenaar <Bram@vim.org> parents: 21550 diff changeset	507 Instead of `:t` you can use `:copy`.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	508
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	509
51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	510 Comparators ~
51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	511
51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	512 The 'ignorecase' option is not used for comparators that use strings.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	513
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	514
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	515 White space ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	516
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	517 Vim9 script enforces proper use of white space. This is no longer allowed: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	518 var name=234 # Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	519 var name= 234 # Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	520 var name =234 # Error!
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	521 There must be white space before and after the "=": >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	522 var name = 234 # OK
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	523 White space must also be put before the # that starts a comment after a
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	524 command: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	525 var name = 234# Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	526 var name = 234 # OK
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	527
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	528 White space is required around most operators.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	529
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	530 White space is not allowed:
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	531 - Between a function name and the "(": >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	532 call Func (arg) # Error!
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	533 call Func
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	534 \ (arg) # Error!
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	535 call Func(arg) # OK
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	536 call Func(
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	537 \ arg) # OK
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	538 call Func(
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	539 \ arg # OK
19473 b09afbebffee patch 8.2.0294: cannot use Ex command that is also a function name Bram Moolenaar <Bram@vim.org> parents: 19404 diff changeset	540 \ )
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	541
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	542
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	543 Conditions and expressions ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	544
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	545 Conditions and expressions are mostly working like they do in other languages.
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	546 Some values are different from legacy Vim script:
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	547 value legacy Vim script Vim9 script ~
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	548 0 falsy falsy
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	549 1 truthy truthy
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	550 99 truthy Error!
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	551 "0" falsy Error!
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	552 "99" truthy Error!
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	553 "text" falsy Error!
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	554
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	555 For the "??" operator and when using "!" then there is no error, every value
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	556 is either falsy or truthy. This is mostly like JavaScript, except that an
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	557 empty list and dict is falsy:
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	558
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	559 type truthy when ~
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	560 bool v:true or 1
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	561 number non-zero
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	562 float non-zero
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	563 string non-empty
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	564 blob non-empty
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	565 list non-empty (different from JavaScript)
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	566 dictionary non-empty (different from JavaScript)
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	567 func when there is a function name
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	568 special v:true
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	569 job when not NULL
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	570 channel when not NULL
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	571 class when not NULL
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	572 object when not NULL (TODO: when isTrue() returns v:true)
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	573
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	574 The boolean operators "\|\|" and "&&" expect the values to be boolean, zero or
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	575 one: >
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	576 1 \|\| false == true
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	577 0 \|\| 1 == true
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	578 0 \|\| false == false
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	579 1 && true == true
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	580 0 && 1 == false
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	581 8 \|\| 0 Error!
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	582 'yes' && 0 Error!
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	583 [] \|\| 99 Error!
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	584
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	585 When using "!" for inverting, there is no error for using any type and the
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	586 result is a boolean. "!!" can be used to turn any value into boolean: >
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	587 !'yes' == false
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	588 !![] == false
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	589 !![1, 2, 3] == true
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	590
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	591 When using "`.."` for string concatenation arguments of simple types are
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	592 always converted to string: >
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	593 'hello ' .. 123 == 'hello 123'
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	594 'hello ' .. v:true == 'hello v:true'
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	595
21771 fcf978444298 patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes Bram Moolenaar <Bram@vim.org> parents: 21717 diff changeset	596 Simple types are string, float, special and bool. For other types \|string()\|
fcf978444298 patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes Bram Moolenaar <Bram@vim.org> parents: 21717 diff changeset	597 can be used.
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	598 false true
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	599 In Vim9 script one can use "true" for v:true and "false" for v:false.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	600
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	601 Indexing a string with [idx] or [idx, idx] uses character indexes instead of
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	602 byte indexes. Example: >
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	603 echo 'bár'[1]
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	604 In legacy script this results in the character 0xc3 (an illegal byte), in Vim9
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	605 script this results in the string 'á'.
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	606
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	607
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	608 What to watch out for ~
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	609 vim9-gotchas
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	610 Vim9 was designed to be closer to often used programming languages, but at the
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	611 same time tries to support the legacy Vim commands. Some compromises had to
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	612 be made. Here is a summary of what might be unexpected.
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	613
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	614 Ex command ranges need to be prefixed with a colon. >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	615 -> # legacy Vim: shifts the previous line to the right
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	616 ->func() # Vim9: method call in continuation line
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	617 :-> # Vim9: shifts the previous line to the right
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	618
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	619 %s/a/b # legacy Vim: substitute on all lines
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	620 x = alongname
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	621 % another # Vim9: line continuation without a backslash
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	622 :%s/a/b # Vim9: substitute on all lines
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	623 'text'->func() # Vim9: method call
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	624 :'t # legacy Vim: jump to mark m
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	625
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	626 Some Ex commands can be confused with assignments in Vim9 script: >
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	627 g:name = value # assignment
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	628 g:pattern:cmd # invalid command - ERROR
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	629 :g:pattern:cmd # :global command
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	630
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	631 Functions defined with `:def` compile the whole function. Legacy functions
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	632 can bail out, and the following lines are not parsed: >
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	633 func Maybe()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	634 if !has('feature')
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	635 return
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	636 endif
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	637 use-feature
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	638 endfunc
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	639 Vim9 functions are compiled as a whole: >
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	640 def Maybe()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	641 if !has('feature')
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	642 return
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	643 endif
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	644 use-feature # May give compilation error
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	645 enddef
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	646 For a workaround, split it in two functions: >
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	647 func Maybe()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	648 if has('feature')
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	649 call MaybyInner()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	650 endif
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	651 endfunc
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	652 if has('feature')
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	653 def MaybeInner()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	654 use-feature
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	655 enddef
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	656 endif
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	657 Or put the unsupported code inside an `if` with a constant expression that
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	658 evaluates to false: >
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	659 def Maybe()
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	660 if has('feature')
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	661 use-feature
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	662 endif
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	663 enddef
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	664 Note that for unrecognized commands there is no check for "\|" and a following
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	665 command. This will give an error for missing `endif`: >
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	666 def Maybe()
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	667 if has('feature') \| use-feature \| endif
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	668 enddef
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	669
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	670 Other differences ~
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	671
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	672 Patterns are used like 'magic' is set, unless explicitly overruled.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	673 The 'edcompatible' option value is not used.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	674 The 'gdefault' option value is not used.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	675
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	676
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	677 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	678
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	679 3. New style functions fast-functions
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	680
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	681 THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	682
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	683 :def
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	684 :def[!] {name}([arguments])[: {return-type}]
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	685 Define a new function by the name {name}. The body of
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	686 the function follows in the next lines, until the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	687 matching `:enddef`.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	688
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	689 When {return-type} is omitted or is "void" the
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	690 function is not expected to return anything.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	691
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	692 {arguments} is a sequence of zero or more argument
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	693 declarations. There are three forms:
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	694 {name}: {type}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	695 {name} = {value}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	696 {name}: {type} = {value}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	697 The first form is a mandatory argument, the caller
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	698 must always provide them.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	699 The second and third form are optional arguments.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	700 When the caller omits an argument the {value} is used.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	701
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	702 The function will be compiled into instructions when
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	703 called, or when `:disassemble` or `:defcompile` is
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	704 used. Syntax and type errors will be produced at that
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	705 time.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	706
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	707 It is possible to nest `:def` inside another `:def` or
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	708 `:function` up to about 50 levels deep.
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	709
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	710 [!] is used as with `:function`. Note that
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	711 script-local functions cannot be deleted or redefined
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	712 later in Vim9 script. They can only be removed by
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	713 reloading the same script.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	714
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	715 :enddef
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	716 :enddef End of a function defined with `:def`. It should be on
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	717 a line by its own.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	718
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	719
19473 b09afbebffee patch 8.2.0294: cannot use Ex command that is also a function name Bram Moolenaar <Bram@vim.org> parents: 19404 diff changeset	720 If the script the function is defined in is Vim9 script, then script-local
b09afbebffee patch 8.2.0294: cannot use Ex command that is also a function name Bram Moolenaar <Bram@vim.org> parents: 19404 diff changeset	721 variables can be accessed without the "s:" prefix. They must be defined
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	722 before the function is compiled. If the script the function is defined in is
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	723 legacy script, then script-local variables must be accessed with the "s:"
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	724 prefix and they do not need to exist (they can be deleted any time).
19473 b09afbebffee patch 8.2.0294: cannot use Ex command that is also a function name Bram Moolenaar <Bram@vim.org> parents: 19404 diff changeset	725
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	726 :defc :defcompile
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	727 :defc[ompile] Compile functions defined in the current script that
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	728 were not compiled yet.
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	729 This will report errors found during the compilation.
19473 b09afbebffee patch 8.2.0294: cannot use Ex command that is also a function name Bram Moolenaar <Bram@vim.org> parents: 19404 diff changeset	730
19404 7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	731 :disa :disassemble
7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	732 :disa[ssemble] {func} Show the instructions generated for {func}.
7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	733 This is for debugging and testing.
19556 ff5048b0ccfe patch 8.2.0335: no completion for :disassemble Bram Moolenaar <Bram@vim.org> parents: 19523 diff changeset	734 Note that for command line completion of {func} you
ff5048b0ccfe patch 8.2.0335: no completion for :disassemble Bram Moolenaar <Bram@vim.org> parents: 19523 diff changeset	735 can prepend "s:" to find script-local functions.
19404 7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	736
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	737 Limitations ~
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	738
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	739 Local variables will not be visible to string evaluation. For example: >
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	740 def EvalString(): list<string>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	741 var list = ['aa', 'bb', 'cc', 'dd']
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	742 return range(1, 2)->map('list[v:val]')
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	743 enddef
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	744
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	745 The map argument is a string expression, which is evaluated without the
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	746 function scope. Instead, use a lambda: >
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	747 def EvalString(): list<string>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	748 var list = ['aa', 'bb', 'cc', 'dd']
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	749 return range(1, 2)->map({ _, v -> list[v] })
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	750 enddef
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	751
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	752
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	753 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	754
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	755 4. Types vim9-types
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	756
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	757 THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	758
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	759 The following builtin types are supported:
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	760 bool
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	761 number
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	762 float
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	763 string
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	764 blob
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	765 list<{type}>
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	766 dict<{type}>
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	767 job
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	768 channel
19646 847a300aa244 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19574 diff changeset	769 func
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	770 func: {type}
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	771 func({type}, ...)
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	772 func({type}, ...): {type}
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	773
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	774 Not supported yet:
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	775 tuple<a: {type}, b: {type}, ...>
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	776
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	777 These types can be used in declarations, but no value will have this type:
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	778 {type}\|{type} {not implemented yet}
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	779 void
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	780 any
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	781
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	782 There is no array type, use list<{type}> instead. For a list constant an
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	783 efficient implementation is used that avoids allocating lot of small pieces of
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	784 memory.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	785
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	786 A partial and function can be declared in more or less specific ways:
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	787 func any kind of function reference, no type
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	788 checking for arguments or return value
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	789 func: {type} any number and type of arguments with specific
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	790 return type
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	791 func({type}) function with argument type, does not return
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	792 a value
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	793 func({type}): {type} function with argument type and return type
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	794 func(?{type}) function with type of optional argument, does
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	795 not return a value
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	796 func(...{type}) function with type of variable number of
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	797 arguments, does not return a value
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	798 func({type}, ?{type}, ...{type}): {type}
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	799 function with:
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	800 - type of mandatory argument
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	801 - type of optional argument
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	802 - type of variable number of arguments
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	803 - return type
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	804
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	805 If the return type is "void" the function does not return a value.
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	806
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	807 The reference can also be a \|Partial\|, in which case it stores extra arguments
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	808 and/or a dictionary, which are not visible to the caller. Since they are
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	809 called in the same way the declaration is the same.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	810
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	811 Custom types can be defined with `:type`: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	812 :type MyList list<string>
21715 571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	813 Custom types must start with a capital letter, to avoid name clashes with
571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	814 builtin types added later, similarly to user functions.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	815 {not implemented yet}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	816
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	817 And classes and interfaces can be used as types: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	818 :class MyClass
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	819 :var mine: MyClass
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	820
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	821 :interface MyInterface
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	822 :var mine: MyInterface
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	823
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	824 :class MyTemplate<Targ>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	825 :var mine: MyTemplate<number>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	826 :var mine: MyTemplate<string>
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	827
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	828 :class MyInterface<Targ>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	829 :var mine: MyInterface<number>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	830 :var mine: MyInterface<string>
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	831 {not implemented yet}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	832
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	833
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	834 Variable types and type casting ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	835 variable-types
21717 ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	836 Variables declared in Vim9 script or in a `:def` function have a type, either
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	837 specified explicitly or inferred from the initialization.
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	838
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	839 Global, buffer, window and tab page variables do not have a specific type, the
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	840 value can be changed at any time, possibly changing the type. Therefore, in
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	841 compiled code the "any" type is assumed.
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	842
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	843 This can be a problem when the "any" type is undesired and the actual type is
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	844 expected to always be the same. For example, when declaring a list: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	845 var l: list<number> = [1, g:two]
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	846 At compile time Vim doesn't know the type of "g:two" and the expression type
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	847 becomes list<any>. An instruction is generated to check the list type before
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	848 doing the assignment, which is a bit inefficient.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	849 type-casting
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	850 To avoid this, use a type cast: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	851 var l: list<number> = [1, <number>g:two]
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	852 The compiled code will then only check that "g:two" is a number and give an
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	853 error if it isn't. This is called type casting.
21717 ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	854
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	855 The syntax of a type cast is: "<" {type} ">". There cannot be white space
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	856 after the "<" or before the ">" (to avoid them being confused with
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	857 smaller-than and bigger-than operators).
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	858
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	859 The semantics is that, if needed, a runtime type check is performed. The
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	860 value is not actually changed. If you need to change the type, e.g. to change
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	861 it to a string, use the \|string()\| function. Or use \|str2nr()\| to convert a
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	862 string to a number.
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	863
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	864
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	865 Type inference ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	866 type-inference
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	867 In general: Whenever the type is clear it can be omitted. For example, when
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	868 declaring a variable and giving it a value: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	869 var name = 0 # infers number type
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	870 var name = 'hello' # infers string type
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	871
21715 571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	872 The type of a list and dictionary comes from the common type of the values.
571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	873 If the values all have the same type, that type is used for the list or
571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	874 dictionary. If there is a mix of types, the "any" type is used. >
571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	875 [1, 2, 3] list<number>
571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	876 ['a', 'b', 'c'] list<string>
571832713efa patch 8.2.1407: Vim9: type of list and dict only depends on first item Bram Moolenaar <Bram@vim.org> parents: 21676 diff changeset	877 [1, 'x', 3] list<any>
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	878
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	879
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	880 Stricter type checking ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	881 type-checking
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	882 In legacy Vim script, where a number was expected, a string would be
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	883 automatically converted to a number. This was convenient for an actual number
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	884 such as "123", but leads to unexpected problems (but no error message) if the
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	885 string doesn't start with a number. Quite often this leads to hard-to-find
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	886 bugs.
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	887
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	888 In Vim9 script this has been made stricter. In most places it works just as
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	889 before, if the value used matches the expected type. There will sometimes be
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	890 an error, thus breaking backwards compatibility. For example:
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	891 - Using a number other than 0 or 1 where a boolean is expected. E1023
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	892 - Using a string value when setting a number options.
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	893 - Using a number where a string is expected. E1024
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	894
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	895 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	896
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	897 5. Namespace, Import and Export
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	898 vim9script vim9-export vim9-import
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	899
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	900 THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	901
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	902 A Vim9 script can be written to be imported. This means that everything in
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	903 the script is local, unless exported. Those exported items, and only those
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	904 items, can then be imported in another script.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	905
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	906 You can cheat by using the global namespace explicitly. We will assume here
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	907 that you don't do that.
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	908
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	909
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	910 Namespace ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	911 :vim9script :vim9
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	912 To recognize a file that can be imported the `vim9script` statement must
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	913 appear as the first statement in the file. It tells Vim to interpret the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	914 script in its own namespace, instead of the global namespace. If a file
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	915 starts with: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	916 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	917 var myvar = 'yes'
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	918 Then "myvar" will only exist in this file. While without `vim9script` it would
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	919 be available as `g:myvar` from any other script and function.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	920
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	921 The variables at the file level are very much like the script-local "s:"
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	922 variables in legacy Vim script, but the "s:" is omitted. And they cannot be
bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	923 deleted.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	924
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	925 In Vim9 script the global "g:" namespace can still be used as before. And the
bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	926 "w:", "b:" and "t:" namespaces. These have in common that variables are not
bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	927 declared and they can be deleted.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	928
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	929 A side effect of `:vim9script` is that the 'cpoptions' option is set to the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	930 Vim default value, like with: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	931 :set cpo&vim
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	932 One of the effects is that \|line-continuation\| is always enabled.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	933 The original value of 'cpoptions' is restored at the end of the script.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	934
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	935
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	936 Export ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	937 :export :exp
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	938 Exporting an item can be written as: >
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	939 export const EXPORTED_CONST = 1234
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	940 export var someValue = ...
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	941 export final someValue = ...
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	942 export const someValue = ...
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	943 export def MyFunc() ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	944 export class MyClass ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	945
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	946 As this suggests, only constants, variables, `:def` functions and classes can
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	947 be exported. {classes are not implemented yet}
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	948
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	949 E1042
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	950 `:export` can only be used in Vim9 script, at the script level.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	951
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	952
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	953 Import ~
20965 59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	954 :import :imp E1094
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	955 The exported items can be imported individually in another Vim9 script: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	956 import EXPORTED_CONST from "thatscript.vim"
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	957 import MyClass from "myclass.vim"
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	958
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	959 To import multiple items at the same time: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	960 import {someValue, MyClass} from "thatscript.vim"
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	961
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	962 In case the name is ambiguous, another name can be specified: >
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	963 import MyClass as ThatClass from "myclass.vim"
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	964 import {someValue, MyClass as ThatClass} from "myclass.vim"
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	965
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	966 To import all exported items under a specific identifier: >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	967 import * as That from 'thatscript.vim'
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	968
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	969 {not implemented yet: using "This as That"}
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	970
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	971 Then you can use "That.EXPORTED_CONST", "That.someValue", etc. You are free
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	972 to choose the name "That", but it is highly recommended to use the name of the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	973 script file to avoid confusion.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	974
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	975 `:import` can also be used in legacy Vim script. The imported items still
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	976 become script-local, even when the "s:" prefix is not given.
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	977
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	978 The script name after `import` can be:
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	979 - A relative path, starting "." or "..". This finds a file relative to the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	980 location of the script file itself. This is useful to split up a large
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	981 plugin into several files.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	982 - An absolute path, starting with "/" on Unix or "D:/" on MS-Windows. This
22723 5b7ea82bc18f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22565 diff changeset	983 will rarely be used.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	984 - A path not being relative or absolute. This will be found in the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	985 "import" subdirectories of 'runtimepath' entries. The name will usually be
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	986 longer and unique, to avoid loading the wrong file.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	987
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	988 Once a vim9 script file has been imported, the result is cached and used the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	989 next time the same script is imported. It will not be read again.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	990 :import-cycle
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	991 The `import` commands are executed when encountered. If that script (directly
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	992 or indirectly) imports the current script, then items defined after the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	993 `import` won't be processed yet. Therefore cyclic imports can exist, but may
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	994 result in undefined items.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	995
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	996
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	997 Import in an autoload script ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	998
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	999 For optimal startup speed, loading scripts should be postponed until they are
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	1000 actually needed. A recommended mechanism:
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1001
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1002 1. In the plugin define user commands, functions and/or mappings that refer to
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1003 an autoload script. >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1004 command -nargs=1 SearchForStuff call searchfor#Stuff(<f-args>)
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1005
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1006 < This goes in .../plugin/anyname.vim. "anyname.vim" can be freely chosen.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1007
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	1008 2. In the autoload script do the actual work. You can import items from
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1009 other files to split up functionality in appropriate pieces. >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1010 vim9script
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1011 import FilterFunc from "../import/someother.vim"
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1012 def searchfor#Stuff(arg: string)
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1013 var filtered = FilterFunc(arg)
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1014 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1015 < This goes in .../autoload/searchfor.vim. "searchfor" in the file name
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1016 must be exactly the same as the prefix for the function name, that is how
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1017 Vim finds the file.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1018
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1019 3. Other functionality, possibly shared between plugins, contains the exported
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1020 items and any private items. >
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1021 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1022 var localVar = 'local'
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1023 export def FilterFunc(arg: string): string
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1024 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1025 < This goes in .../import/someother.vim.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1026
21771 fcf978444298 patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes Bram Moolenaar <Bram@vim.org> parents: 21717 diff changeset	1027 When compiling a `:def` function and a function in an autoload script is
fcf978444298 patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes Bram Moolenaar <Bram@vim.org> parents: 21717 diff changeset	1028 encountered, the script is not loaded until the `:def` function is called.
fcf978444298 patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes Bram Moolenaar <Bram@vim.org> parents: 21717 diff changeset	1029
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1030
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1031 Import in legacy Vim script ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1032
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1033 If an `import` statement is used in legacy Vim script, the script-local "s:"
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1034 namespace will be used for the imported item, even when "s:" is not specified.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1035
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1036
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1037 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1038
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1039 6. Future work: classes vim9-classes
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1040
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1041 Above "class" was mentioned a few times, but it has not been implemented yet.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1042 Most of Vim9 script can be created without this functionality, and since
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1043 implementing classes is going to be a lot of work, it is left for the future.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1044 For now we'll just make sure classes can be added later.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1045
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1046 Thoughts:
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1047 - `class` / `endclass`, everything in one file
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1048 - Class names are always CamelCase
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1049 - Single constructor
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1050 - Single inheritance with `class ThisClass extends BaseClass`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1051 - `abstract class`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1052 - `interface` (Abstract class without any implementation)
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1053 - `class SomeClass implements SomeInterface`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1054 - Generics for class: `class <Tkey, Tentry>`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1055 - Generics for function: `def <Tkey> GetLast(key: Tkey)`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1056
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1057 Again, much of this is from TypeScript.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1058
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1059 Some things that look like good additions:
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1060 - Use a class as an interface (like Dart)
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1061 - Extend a class with methods, using an import (like Dart)
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1062
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1063 An important class that will be provided is "Promise". Since Vim is single
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1064 threaded, connecting asynchronous operations is a natural way of allowing
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1065 plugins to do their work without blocking the user. It's a uniform way to
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1066 invoke callbacks and handle timeouts and errors.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1067
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1068 ==============================================================================
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1069
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1070 9. Rationale vim9-rationale
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1071
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1072 The :def command ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1073
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1074 Plugin writers have asked for much faster Vim script. Investigations have
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	1075 shown that keeping the existing semantics of function calls make this close to
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1076 impossible, because of the overhead involved with calling a function, setting
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1077 up the local function scope and executing lines. There are many details that
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1078 need to be handled, such as error messages and exceptions. The need to create
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1079 a dictionary for a: and l: scopes, the a:000 list and several others add too
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1080 much overhead that cannot be avoided.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1081
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1082 Therefore the `:def` method to define a new-style function had to be added,
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1083 which allows for a function with different semantics. Most things still work
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1084 as before, but some parts do not. A new way to define a function was
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1085 considered the best way to separate the legacy style code from Vim9 style code.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1086
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1087 Using "def" to define a function comes from Python. Other languages use
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1088 "function" which clashes with legacy Vim script.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1089
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1090
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1091 Type checking ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1092
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1093 When compiling lines of Vim commands into instructions as much as possible
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1094 should be done at compile time. Postponing it to runtime makes the execution
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1095 slower and means mistakes are found only later. For example, when
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1096 encountering the "+" character and compiling this into a generic add
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1097 instruction, at execution time the instruction would have to inspect the type
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1098 of the arguments and decide what kind of addition to do. And when the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1099 type is dictionary throw an error. If the types are known to be numbers then
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1100 an "add number" instruction can be used, which is faster. The error can be
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1101 given at compile time, no error handling is needed at runtime, since adding
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1102 two numbers cannot fail.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1103
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1104 The syntax for types, using <type> for compound types, is similar to Java. It
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1105 is easy to understand and widely used. The type names are what were used in
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1106 Vim before, with some additions such as "void" and "bool".
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1107
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1108
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1109 Removing clutter and weirdness ~
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1110
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1111 Once decided that `:def` functions have different syntax than legacy functions,
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1112 we are free to add improvements to make the code more familiar for users who
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1113 know popular programming languages. In other words: remove weird things that
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1114 only Vim does.
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1115
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1116 We can also remove clutter, mainly things that were done to make Vim script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1117 backwards compatible with the good old Vi commands.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1118
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1119 Examples:
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1120 - Drop `:call` for calling a function and `:eval` for manipulating data.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1121 - Drop using a leading backslash for line continuation, automatically figure
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1122 out where an expression ends.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1123
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1124 However, this does require that some things need to change:
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1125 - Comments start with # instead of ", to avoid confusing them with strings.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1126 This is good anyway, it is known from several popular languages.
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1127 - Ex command ranges need to be prefixed with a colon, to avoid confusion with
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1128 expressions (single quote can be a string or a mark, "/" can be divide or a
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1129 search command, etc.).
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1130
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1131 Goal is to limit the differences. A good criteria is that when the old syntax
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1132 is accidentally used you are very likely to get an error message.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1133
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1134
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1135 Syntax and semantics from popular languages ~
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1136
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1137 Script writers have complained that the Vim script syntax is unexpectedly
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1138 different from what they are used to. To reduce this complaint popular
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1139 languages are used as an example. At the same time, we do not want to abandon
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1140 the well-known parts of legacy Vim script.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1141
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1142 For many things TypeScript is followed. It's a recent language that is
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1143 gaining popularity and has similarities with Vim script. It also has a
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1144 mix of static typing (a variable always has a known value type) and dynamic
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1145 typing (a variable can have different types, this changes at runtime). Since
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1146 legacy Vim script is dynamically typed and a lot of existing functionality
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1147 (esp. builtin functions) depends on that, while static typing allows for much
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1148 faster execution, we need to have this mix in Vim9 script.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1149
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1150 There is no intention to completely match TypeScript syntax and semantics. We
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1151 just want to take those parts that we can use for Vim and we expect Vim users
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1152 will be happy with. TypeScript is a complex language with its own history,
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1153 advantages and disadvantages. To get an idea of the disadvantages read the
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1154 book: "JavaScript: The Good Parts". Or find the article "TypeScript: the good
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1155 parts" and read the "Things to avoid" section.
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1156
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1157 People familiar with other languages (Java, Python, etc.) will also find
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1158 things in TypeScript that they do not like or do not understand. We'll try to
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1159 avoid those things.
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1160
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1161 Specific items from TypeScript we avoid:
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1162 - Overloading "+", using it both for addition and string concatenation. This
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1163 goes against legacy Vim script and often leads to mistakes. For that reason
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1164 we will keep using ".." for string concatenation. Lua also uses ".." this
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1165 way. And it allows for conversion to string for more values.
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1166 - TypeScript can use an expression like "99 \|\| 'yes'" in a condition, but
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1167 cannot assign the value to a boolean. That is inconsistent and can be
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1168 annoying. Vim recognizes an expression with && or \|\| and allows using the
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1169 result as a bool. TODO: to be reconsidered
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1170 - TypeScript considers an empty string as Falsy, but an empty list or dict as
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1171 Truthy. That is inconsistent. In Vim an empty list and dict are also
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1172 Falsy.
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1173 - TypeScript has various "Readonly" types, which have limited usefulness,
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1174 since a type cast can remove the immutable nature. Vim locks the value,
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1175 which is more flexible, but is only checked at runtime.
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1176
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1177
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1178 Declarations ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1179
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1180 Legacy Vim script uses `:let` for every assignment, while in Vim9 declarations
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1181 are used. That is different, thus it's good to use a different command:
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1182 `:var`. This is used in many languages. The semantics might be slightly
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1183 different, but it's easily recognized as a declaration.
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1184
23047 29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	1185 Using `:const` for constants is common, but the semantics varies. Some
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1186 languages only make the variable immutable, others also make the value
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1187 immutable. Since "final" is well known from Java for only making the variable
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1188 immutable we decided to use that. And then `:const` can be used for making
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1189 both immutable. This was also used in legacy Vim script and the meaning is
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1190 almost the same.
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1191
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1192 What we end up with is very similar to Dart: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1193 :var name # mutable variable and value
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1194 :final name # immutable variable, mutable value
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1195 :const name # immutable variable and value
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1196
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1197 Since legacy and Vim9 script will be mixed and global variables will be
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1198 shared, optional type checking is desirable. Also, type inference will avoid
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1199 the need for specifying the type in many cases. The TypeScript syntax fits
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1200 best for adding types to declarations: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1201 var name: string # string type is specified
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1202 ...
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1203 name = 'John'
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1204 const greeting = 'hello' # string type is inferred
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1205
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1206 This is how we put types in a declaration: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1207 var mylist: list<string>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1208 final mylist: list<string> = ['foo']
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1209 def Func(arg1: number, arg2: string): bool
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1210
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1211 Two alternatives were considered:
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1212 1. Put the type before the name, like Dart: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1213 var list<string> mylist
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1214 final list<string> mylist = ['foo']
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1215 def Func(number arg1, string arg2) bool
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1216 2. Put the type after the variable name, but do not use a colon, like Go: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1217 var mylist list<string>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1218 final mylist list<string> = ['foo']
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1219 def Func(arg1 number, arg2 string) bool
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1220
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1221 The first is more familiar for anyone used to C or Java. The second one
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1222 doesn't really have an advantage over the first, so let's discard the second.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1223
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1224 Since we use type inference the type can be left out when it can be inferred
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1225 from the value. This means that after `var` we don't know if a type or a name
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1226 follows. That makes parsing harder, not only for Vim but also for humans.
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1227 Also, it will not be allowed to use a variable name that could be a type name,
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1228 using `var string string` is too confusing.
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1229
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1230 The chosen syntax, using a colon to separate the name from the type, adds
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1231 punctuation, but it actually makes it easier to recognize the parts of a
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1232 declaration.
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1233
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1234
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1235 Expressions ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1236
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1237 Expression evaluation was already close to what other languages are doing.
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1238 Some details are unexpected and can be improved. For example a boolean
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1239 condition would accept a string, convert it to a number and check if the
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1240 number is non-zero. This is unexpected and often leads to mistakes, since
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1241 text not starting with a number would be converted to zero, which is
22723 5b7ea82bc18f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22565 diff changeset	1242 considered false. Thus using a string for a condition would often not give an
5b7ea82bc18f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22565 diff changeset	1243 error and be considered false. That is confusing.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1244
23047 29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	1245 In Vim9 type checking is stricter to avoid mistakes. Where a condition is
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1246 used, e.g. with the `:if` command and the `\|\|` operator, only boolean-like
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1247 values are accepted:
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1248 true: `true`, `v:true`, `1`, `0 < 9`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1249 false: `false`, `v:false`, `0`, `0 > 9`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1250 Note that the number zero is false and the number one is true. This is more
22723 5b7ea82bc18f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22565 diff changeset	1251 permissive than most other languages. It was done because many builtin
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1252 functions return these values.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1253
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1254 If you have any type of value and want to use it as a boolean, use the `!!`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1255 operator:
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1256 true: !`!'text'`, `!![99]`, `!!{'x': 1}`, `!!99`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1257 false: `!!''`, `!![]`, `!!{}`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1258
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1259 From a language like JavaScript we have this handy construct: >
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1260 GetName() \|\| 'unknown'
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1261 However, this conflicts with only allowing a boolean for a condition.
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1262 Therefore the "??" operator was added: >
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1263 GetName() ?? 'unknown'
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1264 Here you can explicitly express your intention to use the value as-is and not
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1265 result in a boolean. This is called the \|falsy-operator\|.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1266
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1267
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1268 Import and Export ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1269
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1270 A problem of legacy Vim script is that by default all functions and variables
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1271 are global. It is possible to make them script-local, but then they are not
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1272 available in other scripts. This defies the concept of a package that only
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1273 exports selected items and keeps the rest local.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1274
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	1275 In Vim9 script a mechanism very similar to the JavaScript import and export
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1276 mechanism is supported. It is a variant to the existing `:source` command
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1277 that works like one would expect:
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1278 - Instead of making everything global by default, everything is script-local,
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1279 unless exported.
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1280 - When importing a script the symbols that are imported are explicitly listed,
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1281 avoiding name conflicts and failures if functionality is added later.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1282 - The mechanism allows for writing a big, long script with a very clear API:
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1283 the exported function(s) and class(es).
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1284 - By using relative paths loading can be much faster for an import inside of a
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1285 package, no need to search many directories.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1286 - Once an import has been used, it can be cached and loading it again can be
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1287 avoided.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1288 - The Vim-specific use of "s:" to make things script-local can be dropped.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1289
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1290 When sourcing a Vim9 script from a legacy script, only the items defined
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1291 globally can be used, not the exported items. Alternatives considered:
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1292 - All the exported items become available as script-local items. This makes
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1293 it uncontrollable what items get defined and likely soon leads to trouble.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1294 - Use the exported items and make them global. Disadvantage is that it's then
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1295 not possible to avoid name clashes in the global namespace.
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1296 - Completely disallow sourcing a Vim9 script, require using `:import`. That
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1297 makes it difficult to use scripts for testing, or sourcing them from the
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1298 command line to try them out.
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1299 Note that you can also use `:import` in legacy Vim script, see above.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1300
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1301
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1302 Compiling functions early ~
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1303
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1304 Functions are compiled when called or when `:defcompile` is used. Why not
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1305 compile them early, so that syntax and type errors are reported early?
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1306
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1307 The functions can't be compiled right away when encountered, because there may
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1308 be forward references to functions defined later. Consider defining functions
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1309 A, B and C, where A calls B, B calls C, and C calls A again. It's impossible
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1310 to reorder the functions to avoid forward references.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1311
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1312 An alternative would be to first scan through the file to locate items and
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1313 figure out their type, so that forward references are found, and only then
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1314 execute the script and compile the functions. This means the script has to be
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1315 parsed twice, which is slower, and some conditions at the script level, such
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1316 as checking if a feature is supported, are hard to use. An attempt was made
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1317 to see if it works, but it turned out to be impossible to make work nicely.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1318
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1319 It would be possible to compile all the functions at the end of the script.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1320 The drawback is that if a function never gets called, the overhead of
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1321 compiling it counts anyway. Since startup speed is very important, in most
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1322 cases it's better to do it later and accept that syntax and type errors are
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1323 only reported then. In case these errors should be found early, e.g. when
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1324 testing, the `:defcompile` command will help out.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1325
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1326
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1327 Why not use an embedded language? ~
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1328
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1329 Vim supports interfaces to Perl, Python, Lua, Tcl and a few others. But
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1330 these interfaces have never become widely used, for various reasons. When
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1331 Vim9 was designed a decision was made to make these interfaces lower priority
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1332 and concentrate on Vim script.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1333
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1334 Still, plugin writers may find other languages more familiar, want to use
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1335 existing libraries or see a performance benefit. We encourage plugin authors
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1336 to write code in any language and run it as an external tool, using jobs and
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1337 channels. We can try to make this easier somehow.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1338
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1339 Using an external tool also has disadvantages. An alternative is to convert
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1340 the tool into Vim script. For that to be possible without too much
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1341 translation, and keeping the code fast at the same time, the constructs of the
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1342 tool need to be supported. Since most languages support classes the lack of
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1343 support for classes in Vim is then a problem.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1344
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1345
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1346 Classes ~
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1347
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1348 Vim supports a kind-of object oriented programming by adding methods to a
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1349 dictionary. With some care this can be made to work, but it does not look
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1350 like real classes. On top of that, it's quite slow, because of the use of
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1351 dictionaries.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1352
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1353 The support of classes in Vim9 script is a "minimal common functionality" of
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1354 class support in most languages. It works much like Java, which is the most
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1355 popular programming language.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1356
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1357
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1358
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1359 vim:tw=78:ts=8:noet:ft=help:norl:

Mercurial > vim

annotate runtime/doc/vim9.txt @ 23318:c76240efdf02 v8.2.2204