vim: runtime/doc/vim9.txt annotate

annotate runtime/doc/vim9.txt @ 25282:9bce044c7643 v8.2.3178

patch 8.2.3178: Vim9: the file name of an :import cannot be an expression Commit: https://github.com/vim/vim/commit/4db572eeb2b42819268e934e76c67163316d873f Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jul 18 18:21:38 2021 +0200 patch 8.2.3178: Vim9: the file name of an :import cannot be an expression Problem: Vim9: the file name of an :import cannot be an expression. Solution: Accept an expression that results in a string. Do not support :import in a function.

author	Bram Moolenaar <Bram@vim.org>
date	Sun, 18 Jul 2021 18:30:04 +0200
parents	84c7dc0fdcd2
children	bdda48f01a68

rev	line source
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1 vim9.txt For Vim version 8.2. Last change: 2021 Jul 07
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
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	9 Vim9 script commands and expressions. Vim9 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
23466 15fa3923cc49 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23392 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
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	28 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	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
23938 2a885d095bff patch 8.2.2511: Vim9: cannot use Vim9 script syntax in some places Bram Moolenaar <Bram@vim.org> parents: 23931 diff changeset	54 - a command prefixed with the `vim9cmd` command modifier
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	55
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	56 When using `:function` in a Vim9 script file the legacy syntax is used, with
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	57 the highest \|scriptversion\|. However, this can be confusing and is therefore
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	58 discouraged.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	59
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	60 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	61 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	62 `: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	63
24531 3bfec39ce31c patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script Bram Moolenaar <Bram@vim.org> parents: 24468 diff changeset	64 :vim9[cmd] {cmd} :vim9 :vim9cmd
23938 2a885d095bff patch 8.2.2511: Vim9: cannot use Vim9 script syntax in some places Bram Moolenaar <Bram@vim.org> parents: 23931 diff changeset	65 Execute {cmd} using Vim9 script syntax and semantics.
2a885d095bff patch 8.2.2511: Vim9: cannot use Vim9 script syntax in some places Bram Moolenaar <Bram@vim.org> parents: 23931 diff changeset	66 Useful when typing a command and in a legacy script or
2a885d095bff patch 8.2.2511: Vim9: cannot use Vim9 script syntax in some places Bram Moolenaar <Bram@vim.org> parents: 23931 diff changeset	67 function.
2a885d095bff patch 8.2.2511: Vim9: cannot use Vim9 script syntax in some places Bram Moolenaar <Bram@vim.org> parents: 23931 diff changeset	68
24531 3bfec39ce31c patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script Bram Moolenaar <Bram@vim.org> parents: 24468 diff changeset	69 :leg[acy] {cmd} :leg :legacy
3bfec39ce31c patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script Bram Moolenaar <Bram@vim.org> parents: 24468 diff changeset	70 Execute {cmd} using legacy script syntax and semantics. Only
3bfec39ce31c patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script Bram Moolenaar <Bram@vim.org> parents: 24468 diff changeset	71 useful in a Vim9 script or a :def function.
3bfec39ce31c patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script Bram Moolenaar <Bram@vim.org> parents: 24468 diff changeset	72 Note that {cmd} cannot use local variables, since it is parsed
3bfec39ce31c patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script Bram Moolenaar <Bram@vim.org> parents: 24468 diff changeset	73 with legacy expression syntax.
3bfec39ce31c patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script Bram Moolenaar <Bram@vim.org> parents: 24468 diff changeset	74
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	75 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	76
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	77 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	78
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	79 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	80
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	81 Overview ~
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	82
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	83 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	84 script and `:def` functions; details are below:
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	85 - Comments start with #, not ": >
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	86 echo "hello" # comment
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	87 - Using a backslash for line continuation is hardly ever needed: >
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	88 echo "hello "
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	89 .. yourName
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	90 .. ", how are you?"
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	91 - White space is required in many places.
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	92 - Assign values without `:let`, declare variables with `:var`: >
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	93 var count = 0
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	94 count += 3
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	95 - Constants can be declared with `:final` and `:const`: >
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	96 final matches = [] # add matches
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	97 const names = ['Betty', 'Peter'] # cannot be changed
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	98 - `:final` cannot be used as an abbreviation of `:finally`.
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	99 - Variables and functions are script-local by default.
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	100 - Functions are declared with argument types and return type: >
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	101 def CallMe(count: number, message: string): bool
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	102 - Call functions without `:call`: >
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	103 writefile(['done'], 'file.txt')
24751 e69e7133c9cf Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24569 diff changeset	104 - You cannot use `:xit`, `:t`, `:k`, `:append`, `:change`, `:insert`, `:open`,
e69e7133c9cf Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24569 diff changeset	105 and `:s` or `:d` with only flags.
24128 fcbb1d4df15b patch 8.2.2605: Vim9: string index and slice does not include composing chars Bram Moolenaar <Bram@vim.org> parents: 24103 diff changeset	106 or curly-braces names.
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	107 - A range before a command must be prefixed with a colon: >
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	108 :%s/this/that
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	109 - Unless mentioned specifically, the highest \|scriptversion\| is used.
22441 a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	110
a3bb84cd0f59 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22391 diff changeset	111
20023 c85d4e173cc9 patch 8.2.0567: Vim9: cannot put comments halfway expressions Bram Moolenaar <Bram@vim.org> parents: 20015 diff changeset	112 Comments starting with # ~
c85d4e173cc9 patch 8.2.0567: Vim9: cannot put comments halfway expressions Bram Moolenaar <Bram@vim.org> parents: 20015 diff changeset	113
21353 fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	114 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	115 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	116 # declarations
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	117 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	118
21353 fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	119 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	120 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	121 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	122 by arbitrary text. To avoid confusion only # comments are recognized. This
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	123 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	124
fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	125 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	126 `: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	127 101 number
21353 fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	128
fb8c8fcb7b60 patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing Bram Moolenaar <Bram@vim.org> parents: 21250 diff changeset	129 To improve readability there must be a space between a command and the #
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	130 that starts a comment: >
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	131 var name = value # comment
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	132 var name = value# error!
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	133
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	134 Do not start a comment with #{, it looks like the legacy dictionary literal
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	135 and produces an error where this might be confusing. #{{ or #{{{ are OK,
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	136 these can be used to start a fold.
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	137
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	138 In legacy Vim script # is also used for the alternate file name. In Vim9
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	139 script you need to use %% instead. Instead of ## use %%% (stands for all
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	140 arguments).
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	141
20023 c85d4e173cc9 patch 8.2.0567: Vim9: cannot put comments halfway expressions Bram Moolenaar <Bram@vim.org> parents: 20015 diff changeset	142
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	143 Vim9 functions ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	144
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	145 A function defined with `:def` is compiled. Execution is many times faster,
24408 96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	146 often 10 to 100 times.
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	147
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	148 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	149 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	150
24408 96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	151 Compilation is done when any of these is encountered:
23164 99ef85ff1af4 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23088 diff changeset	152 - the first time the function is called
24408 96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	153 - when the `:defcompile` command is encountered in the script after the
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	154 function was defined
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	155 - `:disassemble` is used for the function.
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	156 - 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	157 reference
24408 96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	158 E1091
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	159 If compilation fails it is not tried again on the next call, instead this
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	160 error is given: "E1091: Function is not compiled: {name}".
24569 e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	161 Compilation will fail when encountering a user command that has not been
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	162 created yet. In this case you can call `execute()` to invoke it at runtime. >
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	163 def MyFunc()
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	164 execute('DefinedLater')
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	165 enddef
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	166
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	167 `: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	168 "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	169 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	170 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	171
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	172 Later classes will be added, which replaces the "dict function" mechanism.
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	173 For now you will need to pass the dictionary explicitly: >
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	174 def DictFunc(d: dict<any>, arg: string)
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	175 echo d[arg]
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	176 enddef
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	177 var d = {item: 'value', func: DictFunc}
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	178 d.func(d, 'item')
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	179
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	180 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	181 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	182 functions.
56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	183
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	184 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	185 There is no "a:" dictionary or "a:000" list.
24408 96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	186 vim9-variable-arguments
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	187 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	188 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	189 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	190 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	191 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	192
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	193 When a function argument is optional (it has a default value) passing `v:none`
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	194 as the argument results in using the default value. This is useful when you
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	195 want to specify a value for an argument that comes after an argument that
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	196 should use its default value. Example: >
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	197 def MyFunc(one = 'one', last = 'last)
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	198 ...
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	199 enddef
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	200 MyFunc(v:none, 'LAST') # first argument uses default value 'one'
24408 96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	201 <
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	202 vim9-ignored-argument
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	203 The argument "_" (an underscore) can be used to ignore the argument. This is
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	204 most useful in callbacks where you don't need it, but do need to give an
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	205 argument to match the call. E.g. when using map() two arguments are passed,
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	206 the key and the value, to ignore the key: >
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	207 map(myList, (_, v) => v * 2)
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	208 There is no error for using the "_" argument multiple times. No type needs to
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	209 be given.
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	210
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	211
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	212 Functions and variables are script-local by default ~
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	213 vim9-scopes
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	214 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	215 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	216 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	217 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	218 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	219 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	220 def s:ThisFunction() # script-local
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	221 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	222 def scriptname#function() # autoload
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	223
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	224 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	225 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	226 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	227 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	228
bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	229 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	230 search for the function:
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	231 - 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	232 - 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	233 - 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	234 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	235 for clarity.
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	236
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	237 Since a script-local function reference can be used without "s:" the name must
24278 4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	238 start with an upper case letter even when using the "s:" prefix. In legacy
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	239 script "s:funcref" could be used, because it could not be referred to with
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	240 "funcref". In Vim9 script it can, therefore "s:Funcref" must be used to avoid
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	241 that the name interferes with builtin functions.
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	242
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	243 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	244 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	245 it is being compiled (to figure out the return type).
20241 56265f711890 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20115 diff changeset	246
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	247 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	248 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	249 variables could be defined anywhere (good luck finding out where!).
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	250
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	251 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	252 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	253 and cannot be deleted or replaced.
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	254
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	255 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	256 that is not (yet) defined, the \|FuncUndefined\| autocommand is not triggered.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	257 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	258 \|FuncUndefined\| triggered there.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	259
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	260
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	261 Reloading a Vim9 script clears functions and variables by default ~
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	262 vim9-reload
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	263 When loading a legacy Vim script a second time nothing is removed, the
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	264 commands will replace existing variables and functions and create new ones.
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	265
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	266 When loading a Vim9 script a second time all existing script-local functions
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	267 and variables are deleted, thus you start with a clean slate. This is useful
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	268 if you are developing a plugin and want to try a new version. If you renamed
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	269 something you don't have to worry about the old name still hanging around.
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	270
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	271 If you do want to keep items, use: >
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	272 vim9script noclear
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	273
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	274 You want to use this in scripts that use a `finish` command to bail out at
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	275 some point when loaded again. E.g. when a buffer local option is set: >
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	276 vim9script noclear
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	277 setlocal completefunc=SomeFunc
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	278 if exists('*g:SomeFunc') \| finish \| endif
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	279 def g:SomeFunc()
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	280 ....
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	281
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	282
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	283 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	284 vim9-declaration :var
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	285 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	286 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	287 section.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	288
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	289 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	290 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	291 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	292 def SomeFunc()
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	293 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	294 if cond
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	295 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	296 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	297
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	298 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	299 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	300 if cond
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	301 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	302 else
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	303 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	304 endif
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	305 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	306
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	307 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	308 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	309 if cond
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	310 inner = 5
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	311 else
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	312 inner = 0
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	313 endif
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	314 echo inner
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	315
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	316 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	317 used: >
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	318 {
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	319 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	320 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	321 }
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	322 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	323
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	324 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	325 zero, false or empty.
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	326
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	327 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	328 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	329 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	330 with `:unlet`.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	331
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	332 `:lockvar` does not work on local variables. Use `:const` and `:final`
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	333 instead.
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	334
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	335 Variables, functions and function arguments cannot shadow previously defined
ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	336 or imported variables and functions in the same script file.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	337 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	338
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	339 Global variables must be prefixed with "g:", also at the script level. >
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	340 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	341 var script_local = 'text'
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	342 g:global = 'value'
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	343 var Funcref = g:ThatFunction
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	344
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	345 Global functions must be prefixed with "g:" when defining them, but can be
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	346 called without "g:". >
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	347 vim9script
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	348 def g:GlobalFunc(): string
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	349 return 'text'
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	350 enddef
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	351 echo GlobalFunc()
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	352 The "g:" prefix is not needed for auto-load functions.
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	353
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	354 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	355 used to repeat a `:substitute` command.
24468 9f41bfdbc6fc Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24426 diff changeset	356 vim9-unpack-ignore
24426 78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	357 For an unpack assignment the underscore can be used to ignore a list item,
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	358 similar to how a function argument can be ignored: >
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	359 [a, _, c] = theList
24468 9f41bfdbc6fc Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24426 diff changeset	360 To ignore any remaining items: >
24426 78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	361 [a, b; _] = longList
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	362
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	363 < E1092
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	364 Declaring more than one variable at a time, using the unpack notation, is
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	365 currently not supported: >
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	366 var [v1, v2] = GetValues() # Error!
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	367 That is because the type needs to be inferred from the list item type, which
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	368 isn't that easy.
78343859f42d patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack Bram Moolenaar <Bram@vim.org> parents: 24408 diff changeset	369
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	370
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	371 Constants ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	372 vim9-const vim9-final
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	373 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	374 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	375 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	376 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	377
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	378 `: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	379 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	380 Example: >
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	381 const myList = [1, 2]
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	382 myList = [3, 4] # Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	383 myList[0] = 9 # Error!
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	384 myList->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	385 < :final
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	386 `: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	387 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	388 final myList = [1, 2]
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	389 myList = [3, 4] # Error!
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	390 myList[0] = 9 # OK
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	391 myList->add(3) # OK
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	392
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	393 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	394
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	395 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	396 final females = ["Mary"]
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	397 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	398 NAMES[0] = ["Jack"] # Error!
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	399 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	400 NAMES[1] = ["Emma"] # Error!
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	401 NAMES[1][0] = "Emma" # OK, now females[0] == "Emma"
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	402
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	403
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	404 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	405
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	406 Functions can be called without `:call`: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	407 writefile(lines, 'file')
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	408 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	409
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	410 A method call without `eval` is possible, so long as the start is an
24128 fcbb1d4df15b patch 8.2.2605: Vim9: string index and slice does not include composing chars Bram Moolenaar <Bram@vim.org> parents: 24103 diff changeset	411 identifier or can't be an Ex command. For a function either "(" or "->" must
fcbb1d4df15b patch 8.2.2605: Vim9: string index and slice does not include composing chars Bram Moolenaar <Bram@vim.org> parents: 24103 diff changeset	412 be following, without a line break. Examples: >
21516 c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	413 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	414 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	415 [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	416 {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	417 "foobar"->Process()
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	418 ("foobar")->Process()
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	419 'foobar'->Process()
c7b2ce90c2de patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit Bram Moolenaar <Bram@vim.org> parents: 21499 diff changeset	420 ('foobar')->Process()
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	421
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	422 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	423 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	424 is both the `:substitute` command and the `substitute()` function. When the
1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	425 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	426 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	427 :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	428
19556 ff5048b0ccfe patch 8.2.0335: no completion for :disassemble Bram Moolenaar <Bram@vim.org> parents: 19523 diff changeset	429 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	430 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	431 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	432 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	433 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	434
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	435
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	436 Omitting function() ~
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	437
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	438 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	439 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	440 The function must already have been defined. >
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	441
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	442 var Funcref = MyFunction
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	443
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	444 When using `function()` the resulting type is "func", a function with any
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	445 number of arguments and any return type (including void). The function can be
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	446 defined later.
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	447
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	448
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	449 Lambda using => instead of -> ~
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	450 vim9-lambda
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	451 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	452 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	453 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	454 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	455
c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	456 To avoid these problems Vim9 script uses a different syntax for a lambda,
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	457 which is similar to JavaScript: >
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	458 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	459
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	460 No line break is allowed in the arguments of a lambda up to and including the
25056 43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	461 "=>" (so that Vim can tell the difference between an expression in parentheses
24911 fd37be6dc258 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24888 diff changeset	462 and lambda arguments). This is OK: >
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	463 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	464 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	465 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	466 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	467 => v > 0)
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	468 This also does not work: >
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	469 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	470 v) => v > 0)
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	471 But you can use a backslash to concatenate the lines before parsing: >
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	472 filter(list, (k,
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	473 \ v)
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	474 \ => v > 0)
24408 96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	475 < vim9-lambda-arguments
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	476 In legacy script a lambda could be called with any number of extra arguments,
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	477 there was no way to warn for not using them. In Vim9 script the number of
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	478 arguments must match. If you do want to accept any arguments, or any further
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	479 arguments, use "..._", which makes the function accept
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	480 \|vim9-variable-arguments\|. Example: >
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	481 var Callback = (..._) => 'anything'
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	482 echo Callback(1, 2, 3) # displays "anything"
96e0b898d5b4 patch 8.2.2744: Vim9: no way to explicitly ignore an argument Bram Moolenaar <Bram@vim.org> parents: 24387 diff changeset	483
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	484 < inline-function
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	485 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	486 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	487 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	488 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	489 }
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	490 This can be useful for a timer, for example: >
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	491 var count = 0
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	492 var timer = timer_start(500, (_) => {
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	493 count += 1
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	494 echom 'Handler called ' .. count
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	495 }, {repeat: 3})
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	496
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	497
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	498 The ending "}" must be at the start of a line. It can be followed by other
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	499 characters, e.g.: >
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	500 var d = mapnew(dict, (k, v): string => {
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	501 return 'value'
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	502 })
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	503 No command can follow the "{", only a comment can be used there.
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	504
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	505 Rationale: The "}" cannot be after a command because it would require parsing
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	506 the commands to find it. For consistency with that no command can follow the
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	507 "{". Unfortunately this means using "() => { command }" does not work, line
cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	508 breaks are always required.
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	509
23737 34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	510 vim9-curly
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	511 To avoid the "{" of a dictionary literal to be recognized as a statement block
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	512 wrap it in parentheses: >
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	513 var Lambda = (arg) => ({key: 42})
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	514
23737 34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	515 Also when confused with the start of a command block: >
34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	516 ({
34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	517 key: value
34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	518 })->method()
34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	519
23318 c76240efdf02 patch 8.2.2204: Vim9: using -> both for method and lambda is confusing Bram Moolenaar <Bram@vim.org> parents: 23305 diff changeset	520
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	521 Automatic line continuation ~
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	522
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	523 In many cases it is obvious that an expression continues on the next line. In
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	524 those cases there is no need to prefix the line with a backslash (see
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	525 \|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	526 var mylist = [
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	527 'one',
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	528 'two',
844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	529 ]
20011 628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	530 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	531 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	532 one: 1,
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	533 two: 2,
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	534 }
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	535 With a function call: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	536 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	537 arg1,
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	538 arg2
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	539 )
628011800942 patch 8.2.0561: Vim9: cannot split function call in multiple lines Bram Moolenaar <Bram@vim.org> parents: 19999 diff changeset	540
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	541 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	542 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	543 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	544 .. middle
bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	545 .. end
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	546 var total = start +
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	547 end -
20013 bf377a9ffccb patch 8.2.0562: Vim9: cannot split an expression into multiple lines Bram Moolenaar <Bram@vim.org> parents: 20011 diff changeset	548 correction
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	549 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	550 ? 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	551 : 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	552
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	553 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	554 before it: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	555 var result = GetBuilder()
20965 59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	556 ->BuilderSetWidth(333)
59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	557 ->BuilderSetHeight(777)
59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	558 ->BuilderBuild()
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	559 var result = MyDict
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	560 .member
20965 59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	561
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	562 For commands that have an argument that is a list of commands, the \| character
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	563 at the start of the line indicates line continuation: >
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	564 autocmd BufNewFile *.match if condition
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	565 \| echo 'match'
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	566 \| endif
517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	567
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	568 Note that this means that in heredoc the first line cannot be a bar: >
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	569 var lines =<< trim END
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	570 \| this doesn't work
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	571 END
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	572 Either use an empty line at the start or do not use heredoc. Or temporarily
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	573 add the "C" flag to 'cpoptions': >
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	574 set cpo+=C
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	575 var lines =<< trim END
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	576 \| this doesn't work
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	577 END
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	578 set cpo-=C
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	579 If the heredoc is inside a function 'cpoptions' must be set before :def and
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	580 restored after the :enddef.
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	581
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	582 In places where line continuation with a backslash is still needed, such as
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	583 splitting up a long Ex command, comments can start with '#\ ': >
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	584 syn region Text
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	585 \ start='foo'
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	586 #\ comment
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	587 \ end='bar'
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	588 Like with legacy script '"\ ' is used. This is also needed when line
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	589 continuation is used without a backslash and a line starts with a bar: >
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	590 au CursorHold * echom 'BEFORE bar'
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	591 #\ some comment
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	592 \| echom 'AFTER bar'
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	593 <
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	594 E1050
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	595 To make it possible for the operator at the start of the line to be
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	596 recognized, it is required to put a colon before a range. This example will
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	597 add "start" and print: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	598 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	599 + print
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	600 Like this: >
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	601 var result = start + print
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	602
20982 bb49b5090a9c patch 8.2.1042: Vim9: cannot put an operator on the next line Bram Moolenaar <Bram@vim.org> parents: 20965 diff changeset	603 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	604 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	605 :+ print
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	606
23047 29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	607 Note that the colon is not required for the \|+cmd\| argument: >
29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	608 edit +6 fname
29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	609
20015 c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	610 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	611 arguments: >
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	612 def MyFunc(
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	613 text: string,
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	614 separator = '-'
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	615 ): string
c001ee73519a patch 8.2.0563: Vim9: cannot split a function line Bram Moolenaar <Bram@vim.org> parents: 20013 diff changeset	616
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	617 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	618 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	619 second line is seen as a separate command: >
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	620 popup_create(some invalid expression, {
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	621 exit_cb: Func})
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	622 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	623 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	624 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	625
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	626 However, the argument of a command that is a command won't be recognized. For
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	627 example, after "windo echo expr" a line break inside "expr" will not be seen.
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	628
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	629
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	630 Notes:
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	631 - "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	632 current function.
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	633 - 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	634 unpacking a list \|:let-unpack\|. This is OK: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	635 [var1, var2] =
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	636 Func()
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	637 < This does not work: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	638 [var1,
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	639 var2] =
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	640 Func()
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	641 - 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	642 similar commands. This is OK: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	643 echo [1,
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	644 2] [3,
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	645 4]
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	646 < This does not work: >
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	647 echo [1, 2]
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	648 [3, 4]
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	649 - In some cases it is difficult for Vim to parse a command, especially when
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	650 commands are used as an argument to another command, such as `windo`. In
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	651 those cases the line continuation with a backslash has to be used.
19999 844c7646f61b patch 8.2.0555: Vim9: line continuation is not always needed Bram Moolenaar <Bram@vim.org> parents: 19968 diff changeset	652
24569 e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	653
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	654 White space ~
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	655
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	656 Vim9 script enforces proper use of white space. This is no longer allowed: >
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	657 var name=234 # Error!
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	658 var name= 234 # Error!
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	659 var name =234 # Error!
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	660 There must be white space before and after the "=": >
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	661 var name = 234 # OK
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	662 White space must also be put before the # that starts a comment after a
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	663 command: >
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	664 var name = 234# Error!
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	665 var name = 234 # OK
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	666
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	667 White space is required around most operators.
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	668
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	669 White space is required in a sublist (list slice) around the ":", except at
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	670 the start and end: >
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	671 otherlist = mylist[v : count] # v:count has a different meaning
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	672 otherlist = mylist[:] # make a copy of the List
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	673 otherlist = mylist[v :]
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	674 otherlist = mylist[: v]
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	675
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	676 White space is not allowed:
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	677 - Between a function name and the "(": >
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	678 Func (arg) # Error!
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	679 Func
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	680 \ (arg) # Error!
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	681 Func
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	682 (arg) # Error!
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	683 Func(arg) # OK
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	684 Func(
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	685 arg) # OK
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	686 Func(
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	687 arg # OK
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	688 )
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	689
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	690
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	691 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	692
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	693 \|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	694
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	695
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	696 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	697
00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	698 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	699 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	700
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	701 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	702 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	703 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	704
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	705 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	706 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	707 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	708 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	709 uses literal keys: >
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	710 var dict = {key: value}
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	711
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	712 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	713 use another character, use a single or double quoted string: >
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	714 var dict = {'key with space': value}
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	715 var dict = {"key\twith\ttabs": value}
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	716 var dict = {'': value} # empty key
23088 285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	717
285cde4b8d0e patch 8.2.2090: Vim9: dict does not accept a key in quotes Bram Moolenaar <Bram@vim.org> parents: 23047 diff changeset	718 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	719 like in JavaScript: >
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	720 var dict = {["key" .. nr]: value}
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	721
23827 7e0d8f1cae7d patch 8.2.2455: Vim9: key type for literal dict and indexing is inconsistent Bram Moolenaar <Bram@vim.org> parents: 23737 diff changeset	722 The key type can be string, number, bool or float. Other types result in an
7e0d8f1cae7d patch 8.2.2455: Vim9: key type for literal dict and indexing is inconsistent Bram Moolenaar <Bram@vim.org> parents: 23737 diff changeset	723 error. A number can be given with and without the []: >
7e0d8f1cae7d patch 8.2.2455: Vim9: key type for literal dict and indexing is inconsistent Bram Moolenaar <Bram@vim.org> parents: 23737 diff changeset	724 var dict = {123: 'without', [456]: 'with'}
7e0d8f1cae7d patch 8.2.2455: Vim9: key type for literal dict and indexing is inconsistent Bram Moolenaar <Bram@vim.org> parents: 23737 diff changeset	725 echo dict
7e0d8f1cae7d patch 8.2.2455: Vim9: key type for literal dict and indexing is inconsistent Bram Moolenaar <Bram@vim.org> parents: 23737 diff changeset	726 {'456': 'with', '123': 'without'}
7e0d8f1cae7d patch 8.2.2455: Vim9: key type for literal dict and indexing is inconsistent Bram Moolenaar <Bram@vim.org> parents: 23737 diff changeset	727
22936 00b0275ffe7f patch 8.2.2015: Vim9: literal dict #{} is not like any other language Bram Moolenaar <Bram@vim.org> parents: 22723 diff changeset	728
23978 54b2aa1f0d42 patch 8.2.2531: Vim9: the :k command is obscure Bram Moolenaar <Bram@vim.org> parents: 23974 diff changeset	729 No :xit, :t, :k, :append, :change or :insert ~
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	730
21584 d0c76ce48326 patch 8.2.1342: Vim9: accidentally using "t" gives a confusing error Bram Moolenaar <Bram@vim.org> parents: 21550 diff changeset	731 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	732 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	733 Instead of `:t` you can use `:copy`.
23978 54b2aa1f0d42 patch 8.2.2531: Vim9: the :k command is obscure Bram Moolenaar <Bram@vim.org> parents: 23974 diff changeset	734 Instead of `:k` you can use `:mark`.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	735
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	736
51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	737 Comparators ~
51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	738
51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	739 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	740
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	741
24569 e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	742 Abort after error ~
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	743
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	744 In legacy script, when an error is encountered, Vim continues to execute
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	745 following lines. This can lead to a long sequence of errors and need to type
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	746 CTRL-C to stop it. In Vim9 script execution of commands stops at the first
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	747 error. Example: >
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	748 vim9script
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	749 var x = does-not-exist
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	750 echo 'not executed'
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	751
e3ec2ec8841a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24531 diff changeset	752
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	753 For loop ~
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	754
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	755 Legacy Vim script has some tricks to make a for loop over a list handle
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	756 deleting items at the current or previous item. In Vim9 script it just uses
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	757 the index, if items are deleted then items in the list will be skipped.
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	758 Example legacy script: >
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	759 let l = [1, 2, 3, 4]
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	760 for i in l
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	761 echo i
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	762 call remove(l, index(l, i))
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	763 endfor
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	764 Would echo:
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	765 1
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	766 2
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	767 3
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	768 4
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	769 In compiled Vim9 script you get:
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	770 1
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	771 3
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	772 Generally, you should not change the list that is iterated over. Make a copy
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	773 first if needed.
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	774
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	775
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	776 Conditions and expressions ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	777
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	778 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	779 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	780 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	781 0 falsy falsy
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	782 1 truthy truthy
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	783 99 truthy Error!
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	784 "0" falsy Error!
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	785 "99" truthy Error!
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	786 "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	787
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	788 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	789 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	790 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	791
ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	792 type truthy when ~
23466 15fa3923cc49 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23392 diff changeset	793 bool true, 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	794 number non-zero
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	795 float non-zero
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	796 string non-empty
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	797 blob non-empty
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	798 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	799 dictionary non-empty (different from JavaScript)
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	800 func when there is a function name
23466 15fa3923cc49 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23392 diff changeset	801 special true or v:true
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	802 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	803 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	804 class when not NULL
23466 15fa3923cc49 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23392 diff changeset	805 object when not NULL (TODO: when isTrue() returns true)
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	806
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	807 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	808 one: >
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	809 1 \|\| false == true
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	810 0 \|\| 1 == true
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	811 0 \|\| false == false
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	812 1 && true == true
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	813 0 && 1 == false
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	814 8 \|\| 0 Error!
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	815 'yes' && 0 Error!
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	816 [] \|\| 99 Error!
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	817
22494 4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	818 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	819 result is a boolean. "!!" can be used to turn any value into boolean: >
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	820 !'yes' == false
22500 ef8a3177edc1 patch 8.2.1798: Vim9: trinary operator condition is too permissive Bram Moolenaar <Bram@vim.org> parents: 22494 diff changeset	821 !![] == false
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	822 !![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	823
4c21f7f6f9e3 patch 8.2.1795: Vim9: operators && and \|\| have a confusing result Bram Moolenaar <Bram@vim.org> parents: 22441 diff changeset	824 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	825 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	826 'hello ' .. 123 == 'hello 123'
23466 15fa3923cc49 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23392 diff changeset	827 'hello ' .. v:true == 'hello true'
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	828
21771 fcf978444298 patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes Bram Moolenaar <Bram@vim.org> parents: 21717 diff changeset	829 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	830 can be used.
23497 2247a2ce3630 patch 8.2.2291: Vim9: cannot use "null" for v:null Bram Moolenaar <Bram@vim.org> parents: 23466 diff changeset	831 false true null
2247a2ce3630 patch 8.2.2291: Vim9: cannot use "null" for v:null Bram Moolenaar <Bram@vim.org> parents: 23466 diff changeset	832 In Vim9 script one can use "true" for v:true, "false" for v:false and "null"
2247a2ce3630 patch 8.2.2291: Vim9: cannot use "null" for v:null Bram Moolenaar <Bram@vim.org> parents: 23466 diff changeset	833 for v:null. When converting a boolean to a string "false" and "true" are
2247a2ce3630 patch 8.2.2291: Vim9: cannot use "null" for v:null Bram Moolenaar <Bram@vim.org> parents: 23466 diff changeset	834 used, not "v:false" and "v:true" like in legacy script. "v:none" is not
2247a2ce3630 patch 8.2.2291: Vim9: cannot use "null" for v:null Bram Moolenaar <Bram@vim.org> parents: 23466 diff changeset	835 changed, it is only used in JSON and has no equivalent in other languages.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	836
24128 fcbb1d4df15b patch 8.2.2605: Vim9: string index and slice does not include composing chars Bram Moolenaar <Bram@vim.org> parents: 24103 diff changeset	837 Indexing a string with [idx] or taking a slice with [idx : idx] uses character
fcbb1d4df15b patch 8.2.2605: Vim9: string index and slice does not include composing chars Bram Moolenaar <Bram@vim.org> parents: 24103 diff changeset	838 indexes instead of byte indexes. Composing characters are included.
fcbb1d4df15b patch 8.2.2605: Vim9: string index and slice does not include composing chars Bram Moolenaar <Bram@vim.org> parents: 24103 diff changeset	839 Example: >
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	840 echo 'bár'[1]
0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	841 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	842 script this results in the string 'á'.
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	843 A negative index is counting from the end, "[-1]" is the last character.
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	844 To exclude the last character use \|slice()\|.
24272 cabed216cc2f patch 8.2.2677: Vim9: cannot use only some of the default arguments Bram Moolenaar <Bram@vim.org> parents: 24150 diff changeset	845 To count composing characters separately use \|strcharpart()\|.
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	846 If the index is out of range then an empty string results.
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	847
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	848 In legacy script "++var" and "--var" would be silently accepted and have no
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	849 effect. This is an error in Vim9 script.
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	850
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	851 Numbers starting with zero are not considered to be octal, only numbers
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	852 starting with "0o" are octal: "0o744". \|scriptversion-4\|
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	853
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	854
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	855 What to watch out for ~
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	856 vim9-gotchas
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	857 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	858 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	859 be made. Here is a summary of what might be unexpected.
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	860
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	861 Ex command ranges need to be prefixed with a colon. >
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	862 -> legacy Vim: shifts the previous line to the right
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	863 ->func() Vim9: method call in a continuation line
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	864 :-> Vim9: shifts the previous line to the right
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	865
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	866 %s/a/b legacy Vim: substitute on all lines
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	867 x = alongname
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	868 % another Vim9: modulo operator in a continuation line
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	869 :%s/a/b Vim9: substitute on all lines
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	870 't legacy Vim: jump to mark t
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	871 'text'->func() Vim9: method call
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	872 :'t Vim9: jump to mark t
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	873
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	874 Some Ex commands can be confused with assignments in Vim9 script: >
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	875 g:name = value # assignment
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	876 g:pattern:cmd # invalid command - ERROR
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	877 :g:pattern:cmd # :global command
21676 1b345fb68ae3 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21584 diff changeset	878
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	879 Functions defined with `:def` compile the whole function. Legacy functions
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	880 can bail out, and the following lines are not parsed: >
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	881 func Maybe()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	882 if !has('feature')
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	883 return
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	884 endif
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	885 use-feature
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	886 endfunc
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	887 Vim9 functions are compiled as a whole: >
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	888 def Maybe()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	889 if !has('feature')
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	890 return
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	891 endif
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	892 use-feature # May give a compilation error
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	893 enddef
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	894 For a workaround, split it in two functions: >
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	895 func Maybe()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	896 if has('feature')
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	897 call MaybeInner()
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	898 endif
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	899 endfunc
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	900 if has('feature')
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	901 def MaybeInner()
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	902 use-feature
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	903 enddef
99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	904 endif
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	905 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	906 evaluates to false: >
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	907 def Maybe()
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	908 if has('feature')
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	909 use-feature
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	910 endif
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	911 enddef
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	912 < vim9-user-command
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	913 Another side effect of compiling a function is that the presence of a user
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	914 command is checked at compile time. If the user command is defined later an
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	915 error will result. This works: >
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	916 command -nargs=1 MyCommand echom <q-args>
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	917 def Works()
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	918 MyCommand 123
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	919 enddef
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	920 This will give an error for "MyCommand" not being defined: >
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	921 def Works()
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	922 command -nargs=1 MyCommand echom <q-args>
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	923 MyCommand 123
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	924 enddef
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	925 A workaround is to invoke the command indirectly with `:execute`: >
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	926 def Works()
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	927 command -nargs=1 MyCommand echom <q-args>
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	928 execute 'MyCommand 123'
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	929 enddef
e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	930
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	931 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	932 command. This will give an error for missing `endif`: >
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	933 def Maybe()
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	934 if has('feature') \| use-feature \| endif
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	935 enddef
21093 99a602b27e0e Runtime file updates Bram Moolenaar <Bram@vim.org> parents: 20982 diff changeset	936
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	937 Other differences ~
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	938
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	939 Patterns are used like 'magic' is set, unless explicitly overruled.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	940 The 'edcompatible' option value is not used.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	941 The 'gdefault' option value is not used.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	942
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	943 You may also find this wiki useful. It was written by an early adopter of
24103 788e10cec9bd Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24024 diff changeset	944 Vim9 script: https://github.com/lacygoill/wiki/blob/master/vim/vim9.md
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	945
25056 43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	946 :++ :--
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	947 The ++ and -- commands have been added. They are very similar to adding or
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	948 subtracting one: >
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	949 ++var
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	950 var += 1
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	951 --var
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	952 var -= 1
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	953
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	954 Using ++var or --var in an expression is not supported yet.
43593a5d873f Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24911 diff changeset	955
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	956 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	957
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	958 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	959
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	960 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	961
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	962 :def
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	963 :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	964 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	965 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	966 matching `:enddef`.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	967
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	968 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	969 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	970
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	971 {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	972 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	973 {name}: {type}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	974 {name} = {value}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	975 {name}: {type} = {value}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	976 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	977 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	978 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	979 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	980
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	981 The function will be compiled into instructions when
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	982 called, or when `:disassemble` or `:defcompile` is
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	983 used. Syntax and type errors will be produced at that
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	984 time.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	985
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	986 It is possible to nest `:def` inside another `:def` or
3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	987 `:function` up to about 50 levels deep.
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	988
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	989 [!] 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	990 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	991 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	992 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	993
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	994 :enddef
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	995 :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	996 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	997
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	998 You may also find this wiki useful. It was written by an early adopter of
24128 fcbb1d4df15b patch 8.2.2605: Vim9: string index and slice does not include composing chars Bram Moolenaar <Bram@vim.org> parents: 24103 diff changeset	999 Vim9 script: https://github.com/lacygoill/wiki/blob/master/vim/vim9.md
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1000
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	1001 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	1002 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	1003 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	1004 legacy script, then script-local variables must be accessed with the "s:"
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	1005 prefix if they do not exist at the time of compiling.
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	1006
20552 74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	1007 :defc :defcompile
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	1008 :defc[ompile] Compile functions defined in the current script that
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	1009 were not compiled yet.
74e3316c1d5a Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20379 diff changeset	1010 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	1011
19404 7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	1012 :disa :disassemble
7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	1013 :disa[ssemble] {func} Show the instructions generated for {func}.
7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	1014 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	1015 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	1016 can prepend "s:" to find script-local functions.
19404 7be3663e2f2b Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19303 diff changeset	1017
24911 fd37be6dc258 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24888 diff changeset	1018 :disa[ssemble] profile {func}
fd37be6dc258 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24888 diff changeset	1019 Like `:disassemble` but with the instructions used for
23737 34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	1020 profiling.
34b4eb3a8458 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23666 diff changeset	1021
24911 fd37be6dc258 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24888 diff changeset	1022 :disa[ssemble] debug {func}
fd37be6dc258 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24888 diff changeset	1023 Like `:disassemble` but with the instructions used for
fd37be6dc258 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24888 diff changeset	1024 debugging.
fd37be6dc258 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24888 diff changeset	1025
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1026 Limitations ~
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1027
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1028 Local variables will not be visible to string evaluation. For example: >
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1029 def MapList(): list<string>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1030 var list = ['aa', 'bb', 'cc', 'dd']
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1031 return range(1, 2)->map('list[v:val]')
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1032 enddef
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1033
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1034 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	1035 function scope. Instead, use a lambda: >
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1036 def MapList(): list<string>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1037 var list = ['aa', 'bb', 'cc', 'dd']
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1038 return range(1, 2)->map(( _, v) => list[v])
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1039 enddef
21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1040
23358 b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1041 The same is true for commands that are not compiled, such as `:global`.
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1042 For these the backtick expansion can be used. Example: >
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1043 def Replace()
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1044 var newText = 'blah'
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1045 g/pattern/s/^/`=newText`/
b3142fc0a414 patch 8.2.2222: Vim9: cannot keep script variables when reloading Bram Moolenaar <Bram@vim.org> parents: 23318 diff changeset	1046 enddef
21250 21fb2a3ad3ca Update runtime files Bram Moolenaar <Bram@vim.org> parents: 21093 diff changeset	1047
24278 4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1048 Closures defined in a loop will share the same context. For example: >
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1049 var flist: list<func>
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1050 for i in range(10)
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1051 var inloop = i
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1052 flist[i] = () => inloop
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1053 endfor
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1054
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1055 The "inloop" variable will exist only once, all closures put in the list refer
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1056 to the same instance, which in the end will have the value 9. This is
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1057 efficient. If you do want a separate context for each closure call a function
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1058 to define it: >
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1059 def GetFunc(i: number): func
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1060 var inloop = i
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1061 return () => inloop
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1062 enddef
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1063
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1064 var flist: list<func>
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1065 for i in range(10)
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1066 flist[i] = GetFunc(i)
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1067 endfor
4ab4ef0c48b1 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 24272 diff changeset	1068
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1069 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1070
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1071 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	1072
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1073 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	1074
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1075 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	1076 bool
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1077 number
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1078 float
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1079 string
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1080 blob
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1081 list<{type}>
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1082 dict<{type}>
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1083 job
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1084 channel
19646 847a300aa244 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19574 diff changeset	1085 func
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1086 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	1087 func({type}, ...)
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1088 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	1089
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1090 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	1091 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	1092
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1093 These types can be used in declarations, but no simple value will actually
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1094 have the "void" type.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1095
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1096 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	1097 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	1098 memory.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1099
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1100 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	1101 func any kind of function reference, no type
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1102 checking for arguments or return value
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1103 func: void any number and type of arguments, no return
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1104 value
19904 bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1105 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	1106 return type
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1107
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1108 func() function with no argument, does not return a
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1109 value
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1110 func(): void same
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1111 func(): {type} function with no argument and return type
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1112
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1113 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	1114 a value
19968 1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1115 func({type}): {type} function with argument type and return type
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1116 func(?{type}) function with type of optional argument, does
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1117 not return a value
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1118 func(...{type}) function with type of variable number of
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1119 arguments, does not return a value
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1120 func({type}, ?{type}, ...{type}): {type}
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1121 function with:
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1122 - type of mandatory argument
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1123 - type of optional argument
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1124 - type of variable number of arguments
1908e92b02fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 19904 diff changeset	1125 - 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	1126
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1127 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	1128
bd4f91762d0f patch 8.2.0508: Vim9: func and partial types not done yet Bram Moolenaar <Bram@vim.org> parents: 19646 diff changeset	1129 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	1130 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	1131 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	1132
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1133 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	1134 :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	1135 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	1136 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	1137 {not implemented yet}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1138
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1139 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	1140 :class MyClass
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1141 :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	1142
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1143 :interface MyInterface
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1144 :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	1145
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1146 :class MyTemplate<Targ>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1147 :var mine: MyTemplate<number>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1148 :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	1149
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1150 :class MyInterface<Targ>
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1151 :var mine: MyInterface<number>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1152 :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	1153 {not implemented yet}
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1154
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1155
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1156 Variable types and type casting ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1157 variable-types
21717 ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	1158 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	1159 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	1160
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	1161 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	1162 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	1163 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	1164
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	1165 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	1166 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	1167 var l: list<number> = [1, g:two]
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	1168 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	1169 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	1170 doing the assignment, which is a bit inefficient.
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	1171 type-casting
fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	1172 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	1173 var l: list<number> = [1, <number>g:two]
23305 fab58304f77d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23164 diff changeset	1174 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	1175 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	1176
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	1177 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	1178 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	1179 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	1180
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	1181 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	1182 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	1183 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	1184 string to a number.
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	1185
ef3b31d510d2 patch 8.2.1408: Vim9: type casting not supported Bram Moolenaar <Bram@vim.org> parents: 21715 diff changeset	1186
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1187 Type inference ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1188 type-inference
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1189 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	1190 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	1191 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	1192 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	1193
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	1194 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	1195 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	1196 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	1197 [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	1198 ['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	1199 [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	1200
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1201 The common type of function references, if they do not all have the same
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1202 number of arguments, uses "(...)" to indicate the number of arguments is not
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1203 specified. For example: >
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1204 def Foo(x: bool)
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1205 enddef
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1206 def Bar(x: bool, y: bool)
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1207 enddef
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1208 var funclist = [Foo, Bar]
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1209 echo funclist->typename()
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1210 Results in:
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1211 list<func(...)>
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1212
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	1213 For script-local variables in Vim9 script the type is checked, also when the
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	1214 variable was declared in a legacy function.
5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	1215
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1216
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1217 Stricter type checking ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1218 type-checking
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1219 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	1220 automatically converted to a number. This was convenient for an actual number
24387 5c98ea5f5d6e Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24278 diff changeset	1221 such as "123", but leads to unexpected problems (and no error message) if the
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1222 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	1223 bugs.
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1224
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1225 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	1226 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	1227 an error, thus breaking backwards compatibility. For example:
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1228 - Using a number other than 0 or 1 where a boolean is expected. E1023
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1229 - Using a string value when setting a number option.
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1230 - Using a number where a string is expected. E1024
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1231
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	1232 One consequence is that the item type of a list or dict given to map() must
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	1233 not change. This will give an error in Vim9 script: >
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1234 vim9 echo map([1, 2, 3], (i, v) => 'item ' .. i)
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	1235 E1012: Type mismatch; expected number but got string
25161 84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1236 Instead use \|mapnew(): >
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1237 vim9 echo mapnew([1, 2, 3], (i, v) => 'item ' .. i)
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1238 ['item 0', 'item 1', 'item 2']
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1239
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1240 If the item type was determined to be "any" it can change to a more specific
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1241 type. E.g. when a list of mixed types gets changed to a list of numbers: >
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1242 var mylist = [1, 2.0, '3']
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1243 # typename(mylist) == "list<any>"
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1244 map(mylist, (i, v) => 'item ' .. i)
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1245 # typename(mylist) == "list<string>", no error
84c7dc0fdcd2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 25056 diff changeset	1246
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	1247 Same for \|extend()\|, use \|extendnew()\| instead, and for \|flatten()\|, use
ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	1248 \|flattennew()\| instead.
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	1249
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1250 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1251
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1252 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	1253 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	1254
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1255 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	1256
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1257 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	1258 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	1259 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	1260
21991 bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1261 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	1262 that you don't do that.
bbca88cd13d5 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21825 diff changeset	1263
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1264
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1265 Namespace ~
23392 517fca70e084 patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient Bram Moolenaar <Bram@vim.org> parents: 23360 diff changeset	1266 vim9-namespace
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	1267 To recognize a file that can be imported the `vim9script` statement must
23974 d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1268 appear as the first statement in the file (see \|vim9-mix\| for an exception).
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1269 It tells Vim to interpret the script in its own namespace, instead of the
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1270 global namespace. If a file starts with: >
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1271 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1272 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	1273 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	1274 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	1275
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1276 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	1277 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	1278 deleted.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1279
20115 bd021eb62e73 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20023 diff changeset	1280 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	1281 "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	1282 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	1283
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1284 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	1285 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	1286 :set cpo&vim
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1287 One of the effects is that \|line-continuation\| is always enabled.
24150 4919f2d8d7fd patch 8.2.2616: Vim9: if 'cpo' is change in Vim9 script it may be restored Bram Moolenaar <Bram@vim.org> parents: 24128 diff changeset	1288 The original value of 'cpoptions' is restored at the end of the script, while
4919f2d8d7fd patch 8.2.2616: Vim9: if 'cpo' is change in Vim9 script it may be restored Bram Moolenaar <Bram@vim.org> parents: 24128 diff changeset	1289 flags added or removed in the script are also added to or removed from the
4919f2d8d7fd patch 8.2.2616: Vim9: if 'cpo' is change in Vim9 script it may be restored Bram Moolenaar <Bram@vim.org> parents: 24128 diff changeset	1290 original value to get the same effect. The order of flags may change.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1291
23974 d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1292 vim9-mix
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1293 There is one way to use both legacy and Vim9 syntax in one script file: >
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1294 " comments may go here
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1295 if !has('vim9script')
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1296 " legacy script commands go here
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1297 finish
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1298 endif
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1299 vim9script
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1300 # Vim9 script commands go here
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1301 This allows for writing a script that takes advantage of the Vim9 script
24024 ef454a7f485d Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23978 diff changeset	1302 syntax if possible, but will also work on a Vim version without it.
23974 d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1303
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1304 This can only work in two ways:
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1305 1. The "if" statement evaluates to false, the commands up to `endif` are
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1306 skipped and `vim9script` is then the first command actually executed.
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1307 2. The "if" statement evaluates to true, the commands up to `endif` are
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1308 executed and `finish` bails out before reaching `vim9script`.
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1309
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1310 TODO: The "vim9script" feature does not exist yet, it will only be added once
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1311 the Vim9 script syntax has been fully implemented.
d4f7e4138544 patch 8.2.2529: Vim9: Not possible to use legacy and Vim9 script in one file Bram Moolenaar <Bram@vim.org> parents: 23938 diff changeset	1312
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1313
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1314 Export ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1315 :export :exp
21499 3a1ed539ae2a Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21353 diff changeset	1316 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	1317 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	1318 export var someValue = ...
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1319 export final someValue = ...
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1320 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	1321 export def MyFunc() ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1322 export class MyClass ...
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1323 export interface MyClass ...
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1324
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1325 As this suggests, only constants, variables, `:def` functions and classes can
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1326 be exported. {not implemented yet: class, interface}
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1327
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1328 E1042
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1329 `: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	1330
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1331
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1332 Import ~
20965 59f93c2d2551 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20856 diff changeset	1333 :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	1334 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	1335 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	1336 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	1337
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1338 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	1339 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	1340
19303 51bc26d4a393 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 19181 diff changeset	1341 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	1342 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	1343 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	1344
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1345 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	1346 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	1347
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1348 {not implemented yet: using "This as That"}
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1349
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1350 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	1351 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	1352 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	1353
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1354 `: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	1355 become script-local, even when the "s:" prefix is not given.
d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1356
25282 9bce044c7643 patch 8.2.3178: Vim9: the file name of an :import cannot be an expression Bram Moolenaar <Bram@vim.org> parents: 25161 diff changeset	1357 `:import` can not be used in a function. Imported items are intended to exist
9bce044c7643 patch 8.2.3178: Vim9: the file name of an :import cannot be an expression Bram Moolenaar <Bram@vim.org> parents: 25161 diff changeset	1358 at the script level and only imported once.
9bce044c7643 patch 8.2.3178: Vim9: the file name of an :import cannot be an expression Bram Moolenaar <Bram@vim.org> parents: 25161 diff changeset	1359
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1360 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	1361 - 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	1362 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	1363 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	1364 - 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	1365 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	1366 - 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	1367 "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	1368 longer and unique, to avoid loading the wrong file.
25282 9bce044c7643 patch 8.2.3178: Vim9: the file name of an :import cannot be an expression Bram Moolenaar <Bram@vim.org> parents: 25161 diff changeset	1369 Note that "after/import" is not used.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1370
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1371 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	1372 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	1373 :import-cycle
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1374 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	1375 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	1376 `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	1377 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	1378
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1379
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1380 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	1381
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1382 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	1383 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	1384
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1385 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	1386 an autoload script. >
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	1387 command -nargs=1 SearchForStuff searchfor#Stuff(<f-args>)
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1388
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1389 < 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	1390
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	1391 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	1392 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	1393 vim9script
23573 e2e2cc5d0856 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23497 diff changeset	1394 import FilterFunc from "../import/someother.vim"
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1395 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	1396 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	1397 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1398 < 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	1399 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	1400 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	1401
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1402 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	1403 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	1404 vim9script
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1405 var localVar = 'local'
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1406 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	1407 ...
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1408 < 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	1409
21771 fcf978444298 patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes Bram Moolenaar <Bram@vim.org> parents: 21717 diff changeset	1410 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	1411 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	1412
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1413
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1414 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	1415
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1416 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	1417 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	1418
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1419
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1420 ==============================================================================
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1421
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1422 6. Future work: classes vim9-classes
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1423
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1424 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	1425 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	1426 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	1427 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	1428
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1429 Thoughts:
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1430 - `class` / `endclass`, the whole class must be in one file
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1431 - Class names are always CamelCase (to avoid a name clash with builtin types)
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1432 - A single constructor called "constructor"
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1433 - Single inheritance with `class ThisClass extends BaseClass`
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1434 - `abstract class` (class with incomplete implementation)
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1435 - `interface` / `endinterface` (abstract class without any implementation)
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1436 - `class SomeClass implements SomeInterface`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1437 - Generics for class: `class <Tkey, Tentry>`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1438 - Generics for function: `def <Tkey> GetLast(key: Tkey)`
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1439
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1440 Again, much of this is from TypeScript with a slightly different syntax.
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1441
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1442 Some things that look like good additions:
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1443 - Use a class as an interface (like Dart)
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1444 - Extend a class with methods, using an import (like Dart)
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1445 - Mixins
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1446 - For testing: Mock mechanism
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1447
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1448 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	1449 threaded, connecting asynchronous operations is a natural way of allowing
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1450 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	1451 invoke callbacks and handle timeouts and errors.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1452
24888 b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1453 Some examples: >
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1454
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1455 abstract class Person
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1456 static const prefix = 'xxx'
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1457 var name: string
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1458
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1459 def constructor(name: string)
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1460 this.name = name;
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1461 enddef
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1462
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1463 def display(): void
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1464 echo name
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1465 enddef
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1466
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1467 abstract def find(string): Person
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1468 endclass
b6ac4ed5e2d2 patch 8.2.2982: Vim9: future commands are not reserved yet Bram Moolenaar <Bram@vim.org> parents: 24751 diff changeset	1469
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1470 ==============================================================================
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1471
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1472 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	1473
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1474 The :def command ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1475
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1476 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	1477 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	1478 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	1479 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	1480 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	1481 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	1482 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	1483
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1484 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	1485 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	1486 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	1487 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	1488
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1489 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	1490 "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	1491
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1492
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1493 Type checking ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1494
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1495 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	1496 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	1497 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	1498 encountering the "+" character and compiling this into a generic add
23666 96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	1499 instruction, at runtime the instruction would have to inspect the type of the
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	1500 arguments and decide what kind of addition to do. And when the type is
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	1501 dictionary throw an error. If the types are known to be numbers then an "add
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	1502 number" instruction can be used, which is faster. The error can be given at
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	1503 compile time, no error handling is needed at runtime, since adding two numbers
96206643bd9f Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 23573 diff changeset	1504 cannot fail.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1505
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1506 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	1507 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	1508 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	1509
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1510
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1511 Removing clutter and weirdness ~
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1512
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1513 Once decided that `:def` functions have different syntax than legacy functions,
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1514 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	1515 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	1516 only Vim does.
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1517
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1518 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	1519 backwards compatible with the good old Vi commands.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1520
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1521 Examples:
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1522 - Drop `:call` for calling a function and `:eval` for manipulating data.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1523 - Drop using a leading backslash for line continuation, automatically figure
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1524 out where an expression ends.
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1525
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1526 However, this does require that some things need to change:
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1527 - 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	1528 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	1529 - 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	1530 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	1531 search command, etc.).
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1532
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1533 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	1534 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	1535
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1536
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1537 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	1538
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1539 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	1540 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	1541 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	1542 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	1543
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1544 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	1545 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	1546 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	1547 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	1548 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	1549 (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	1550 faster execution, we need to have this mix in Vim9 script.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1551
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1552 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	1553 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	1554 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	1555 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	1556 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	1557 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	1558
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1559 People familiar with other languages (Java, Python, etc.) will also find
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1560 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	1561 avoid those things.
22272 eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1562
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1563 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	1564 - 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	1565 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	1566 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	1567 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	1568 - 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	1569 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	1570 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	1571 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	1572 - 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	1573 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	1574 Falsy.
eb1f5f618c75 patch 8.2.1685: Vim9: cannot declare a constant value Bram Moolenaar <Bram@vim.org> parents: 22171 diff changeset	1575 - 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	1576 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	1577 which is more flexible, but is only checked at runtime.
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1578
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1579
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1580 Declarations ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1581
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1582 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	1583 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	1584 `: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	1585 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	1586
23047 29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	1587 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	1588 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	1589 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	1590 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	1591 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	1592 almost the same.
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1593
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1594 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	1595 :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	1596 :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	1597 :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	1598
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1599 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	1600 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	1601 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	1602 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	1603 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	1604 ...
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1605 name = 'John'
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1606 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	1607
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1608 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	1609 var mylist: list<string>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1610 final mylist: list<string> = ['foo']
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1611 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	1612
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1613 Two alternatives were considered:
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1614 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	1615 var list<string> mylist
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1616 final list<string> mylist = ['foo']
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1617 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	1618 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	1619 var mylist list<string>
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1620 final mylist list<string> = ['foo']
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1621 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	1622
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1623 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	1624 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	1625
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1626 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	1627 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	1628 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	1629 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	1630 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	1631
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1632 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	1633 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	1634 declaration.
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1635
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1636
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1637 Expressions ~
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1638
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1639 Expression evaluation was already close to what other languages are doing.
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1640 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	1641 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	1642 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	1643 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	1644 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	1645 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	1646
23047 29c5f168c6fd Update runtime files Bram Moolenaar <Bram@vim.org> parents: 22958 diff changeset	1647 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	1648 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	1649 values are accepted:
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1650 true: `true`, `v:true`, `1`, `0 < 9`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1651 false: `false`, `v:false`, `0`, `0 > 9`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1652 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	1653 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	1654 functions return these values.
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1655
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1656 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	1657 operator:
24751 e69e7133c9cf Update runtime files Bram Moolenaar <Bram@vim.org> parents: 24569 diff changeset	1658 true: `!!'text'`, `!![99]`, `!!{'x': 1}`, `!!99`
22565 17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1659 false: `!!''`, `!![]`, `!!{}`
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1660
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1661 From a language like JavaScript we have this handy construct: >
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1662 GetName() \|\| 'unknown'
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1663 However, this conflicts with only allowing a boolean for a condition.
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1664 Therefore the "??" operator was added: >
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1665 GetName() ?? 'unknown'
17c4178f26ea Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22500 diff changeset	1666 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	1667 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	1668
a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1669
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1670 Import and Export ~
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1671
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1672 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	1673 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	1674 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	1675 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	1676
21825 0db0640e16e0 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21771 diff changeset	1677 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	1678 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	1679 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	1680 - 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	1681 unless exported.
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1682 - 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	1683 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	1684 - 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	1685 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	1686 - 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	1687 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	1688 - 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	1689 avoided.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1690 - 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	1691
20856 83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1692 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	1693 globally can be used, not the exported items. Alternatives considered:
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1694 - 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	1695 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	1696 - 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	1697 not possible to avoid name clashes in the global namespace.
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1698 - Completely disallow sourcing a Vim9 script, require using `:import`. That
83cfa1ef1bf2 Update runtime files Bram Moolenaar <Bram@vim.org> parents: 20552 diff changeset	1699 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	1700 command line to try them out.
22171 d4c7b3e9cd17 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 21991 diff changeset	1701 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	1702
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1703
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1704 Compiling functions early ~
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1705
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1706 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	1707 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	1708
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1709 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	1710 be forward references to functions defined later. Consider defining functions
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1711 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	1712 to reorder the functions to avoid forward references.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1713
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1714 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	1715 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	1716 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	1717 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	1718 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	1719 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	1720
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1721 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	1722 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	1723 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	1724 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	1725 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	1726 testing, the `:defcompile` command will help out.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1727
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1728
22391 a9fb7efa31d6 patch 8.2.1744: Vim9: using ":const!" is weird Bram Moolenaar <Bram@vim.org> parents: 22328 diff changeset	1729 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	1730
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1731 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	1732 these interfaces have never become widely used, for various reasons. When
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1733 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	1734 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	1735
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1736 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	1737 existing libraries or see a performance benefit. We encourage plugin authors
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1738 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	1739 channels. We can try to make this easier somehow.
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1740
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1741 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	1742 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	1743 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	1744 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	1745 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	1746
22328 75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1747
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1748 Classes ~
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1749
75ff30a78189 Update runtime files. Bram Moolenaar <Bram@vim.org> parents: 22272 diff changeset	1750 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	1751 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	1752 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	1753 dictionaries.
19181 94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1754
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1755 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	1756 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	1757 popular programming language.
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1758
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1759
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1760
94eda51ba9ba patch 8.2.0149: maintaining a Vim9 branch separately is more work Bram Moolenaar <Bram@vim.org> parents: diff changeset	1761 vim:tw=78:ts=8:noet:ft=help:norl:

Mercurial > vim

annotate runtime/doc/vim9.txt @ 25282:9bce044c7643 v8.2.3178