Mercurial > vim
annotate runtime/doc/vim9.txt @ 27459:5825405e4e2c
Update runtime files
Commit: https://github.com/vim/vim/commit/f10911e5db16f1fe6ab519c5d091ad0c1df0d063
Author: Bram Moolenaar <Bram@vim.org>
Date: Sat Jan 29 22:20:48 2022 +0000
Update runtime files
author | Bram Moolenaar <Bram@vim.org> |
---|---|
date | Sat, 29 Jan 2022 23:30:04 +0100 |
parents | 3649b5a6b1b6 |
children | 4789f29c9595 |
rev | line source |
---|---|
27459 | 1 *vim9.txt* For Vim version 8.2. Last change: 2022 Jan 29 |
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 |
23392
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
7 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
|
8 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
9 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
|
10 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
|
11 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
12 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
13 |
23466 | 14 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
|
15 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
|
16 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
|
17 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
|
18 5. Namespace, Import and Export |vim9script| |
22328 | 19 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
|
20 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
21 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
|
22 |
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 |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
25 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
|
26 |
20241 | 27 Vim script has been growing over time, while preserving backwards |
28 compatibility. That means bad choices from the past often can't be changed | |
20965 | 29 and compatibility with Vi restricts possible solutions. Execution is quite |
20241 | 30 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
|
31 |
20241 | 32 The main goal of Vim9 script is to drastically improve performance. This is |
33 accomplished by compiling commands into instructions that can be efficiently | |
34 executed. An increase in execution speed of 10 to 100 times can be expected. | |
35 | |
36 A secondary goal is to avoid Vim-specific constructs and get closer to | |
37 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
|
38 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
39 The performance improvements can only be achieved by not being 100% backwards |
20552 | 40 compatible. For example, making function arguments available in the |
41 "a:" dictionary adds quite a lot of overhead. In a Vim9 function this | |
42 dictionary is not available. Other differences are more subtle, such as how | |
43 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
|
44 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
45 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
|
46 - 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
|
47 - a script file where the first command is `vim9script` |
22328 | 48 - 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
|
49 - 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
|
50 |
23573 | 51 When using `:function` in a Vim9 script file the legacy syntax is used, with |
52 the highest |scriptversion|. However, this can be confusing and is therefore | |
53 discouraged. | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
54 |
20241 | 55 Vim9 script and legacy Vim script can be mixed. There is no requirement to |
22328 | 56 rewrite old scripts, they keep working as before. You may want to use a few |
57 `: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
|
58 |
24531
3bfec39ce31c
patch 8.2.2805: Vim9: cannot use legacy syntax in Vim9 script
Bram Moolenaar <Bram@vim.org>
parents:
24468
diff
changeset
|
59 :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
|
60 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
|
61 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
|
62 function. |
2a885d095bff
patch 8.2.2511: Vim9: cannot use Vim9 script syntax in some places
Bram Moolenaar <Bram@vim.org>
parents:
23931
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 :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
|
65 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
|
66 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
|
67 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
|
68 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
|
69 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
70 ============================================================================== |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
71 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
72 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
|
73 |
22441 | 74 Overview ~ |
75 | |
76 Brief summary of the differences you will most often encounter when using Vim9 | |
77 script and `:def` functions; details are below: | |
78 - Comments start with #, not ": > | |
23573 | 79 echo "hello" # comment |
22441 | 80 - Using a backslash for line continuation is hardly ever needed: > |
23573 | 81 echo "hello " |
22441 | 82 .. yourName |
83 .. ", how are you?" | |
26769
30972227ac8d
patch 8.2.3913: help for expressions does not mention Vim9 syntax
Bram Moolenaar <Bram@vim.org>
parents:
26755
diff
changeset
|
84 - White space is required in many places to improve readability. |
27459 | 85 - Assign values without `:let` *E1126* , declare variables with `:var`: > |
23573 | 86 var count = 0 |
22441 | 87 count += 3 |
88 - Constants can be declared with `:final` and `:const`: > | |
23573 | 89 final matches = [] # add matches |
22441 | 90 const names = ['Betty', 'Peter'] # cannot be changed |
91 - `:final` cannot be used as an abbreviation of `:finally`. | |
92 - Variables and functions are script-local by default. | |
93 - Functions are declared with argument types and return type: > | |
94 def CallMe(count: number, message: string): bool | |
95 - Call functions without `:call`: > | |
23573 | 96 writefile(['done'], 'file.txt') |
26769
30972227ac8d
patch 8.2.3913: help for expressions does not mention Vim9 syntax
Bram Moolenaar <Bram@vim.org>
parents:
26755
diff
changeset
|
97 - You cannot use old Ex commands `:xit`, `:t`, `:k`, `:append`, `:change`, |
30972227ac8d
patch 8.2.3913: help for expressions does not mention Vim9 syntax
Bram Moolenaar <Bram@vim.org>
parents:
26755
diff
changeset
|
98 `:insert`, `:open`, and `:s` or `:d` with only flags. |
25973 | 99 - You cannot use curly-braces names. |
22441 | 100 - A range before a command must be prefixed with a colon: > |
23573 | 101 :%s/this/that |
25700 | 102 - Executing a register with "@r" does not work, you can prepend a colon or use |
103 `:exe`: > | |
104 :exe @a | |
23573 | 105 - Unless mentioned specifically, the highest |scriptversion| is used. |
27162 | 106 - When defining an expression mapping, the expression will be evaluated in the |
107 context of the script where it was defined. | |
22441 | 108 |
109 | |
20023
c85d4e173cc9
patch 8.2.0567: Vim9: cannot put comments halfway expressions
Bram Moolenaar <Bram@vim.org>
parents:
20015
diff
changeset
|
110 Comments starting with # ~ |
c85d4e173cc9
patch 8.2.0567: Vim9: cannot put comments halfway expressions
Bram Moolenaar <Bram@vim.org>
parents:
20015
diff
changeset
|
111 |
21353
fb8c8fcb7b60
patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing
Bram Moolenaar <Bram@vim.org>
parents:
21250
diff
changeset
|
112 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
|
113 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
|
114 # declarations |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
115 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
|
116 |
21353
fb8c8fcb7b60
patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing
Bram Moolenaar <Bram@vim.org>
parents:
21250
diff
changeset
|
117 The reason is that a double quote can also be the start of a string. In many |
21825 | 118 places, especially halfway through an expression with a line break, it's hard |
119 to tell what the meaning is, since both a string and a comment can be followed | |
120 by arbitrary text. To avoid confusion only # comments are recognized. This | |
121 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
|
122 |
fb8c8fcb7b60
patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing
Bram Moolenaar <Bram@vim.org>
parents:
21250
diff
changeset
|
123 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
|
124 `:number` for that. > |
27036 | 125 :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
|
126 |
fb8c8fcb7b60
patch 8.2.1227: Vim9: allowing both quoted and # comments is confusing
Bram Moolenaar <Bram@vim.org>
parents:
21250
diff
changeset
|
127 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
|
128 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
|
129 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
|
130 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
|
131 |
24272
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
132 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
|
133 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
|
134 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
|
135 |
23392
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
136 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
|
137 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
|
138 arguments). |
20115 | 139 |
20023
c85d4e173cc9
patch 8.2.0567: Vim9: cannot put comments halfway expressions
Bram Moolenaar <Bram@vim.org>
parents:
20015
diff
changeset
|
140 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
141 Vim9 functions ~ |
27459 | 142 *E1099* |
20241 | 143 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
|
144 often 10 to 100 times. |
20241 | 145 |
20552 | 146 Many errors are already found when compiling, before the function is executed. |
20241 | 147 The syntax is strict, to enforce code that is easy to read and understand. |
148 | |
24408
96e0b898d5b4
patch 8.2.2744: Vim9: no way to explicitly ignore an argument
Bram Moolenaar <Bram@vim.org>
parents:
24387
diff
changeset
|
149 Compilation is done when any of these is encountered: |
23164 | 150 - 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
|
151 - when the `:defcompile` command is encountered in the script after the |
21991 | 152 function was defined |
153 - `:disassemble` is used for the function. | |
154 - a function that is compiled calls the function or uses it as a function | |
25700 | 155 reference (so that the argument and return types can be checked) |
24408
96e0b898d5b4
patch 8.2.2744: Vim9: no way to explicitly ignore an argument
Bram Moolenaar <Bram@vim.org>
parents:
24387
diff
changeset
|
156 *E1091* |
96e0b898d5b4
patch 8.2.2744: Vim9: no way to explicitly ignore an argument
Bram Moolenaar <Bram@vim.org>
parents:
24387
diff
changeset
|
157 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
|
158 error is given: "E1091: Function is not compiled: {name}". |
24569 | 159 Compilation will fail when encountering a user command that has not been |
160 created yet. In this case you can call `execute()` to invoke it at runtime. > | |
161 def MyFunc() | |
162 execute('DefinedLater') | |
163 enddef | |
20552 | 164 |
165 `:def` has no options like `:function` does: "range", "abort", "dict" or | |
23164 | 166 "closure". A `:def` function always aborts on an error (unless `:silent!` was |
26708 | 167 used for the command or the error was caught a `:try` block), does not get a |
168 range passed cannot be a "dict" function, and can always be a closure. | |
25700 | 169 *vim9-no-dict-function* |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
170 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
|
171 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
|
172 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
|
173 echo d[arg] |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
174 enddef |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
175 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
|
176 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
|
177 |
25836 | 178 You can call a legacy dict function though: > |
179 func Legacy() dict | |
180 echo self.value | |
181 endfunc | |
182 def CallLegacy() | |
183 var d = {func: Legacy, value: 'text'} | |
184 d.func() | |
185 enddef | |
27459 | 186 < *E1096* |
20241 | 187 The argument types and return type need to be specified. The "any" type can |
188 be used, type checking will then be done at runtime, like with legacy | |
189 functions. | |
27459 | 190 *E1106* |
21825 | 191 Arguments are accessed by name, without "a:", just like any other language. |
192 There is no "a:" dictionary or "a:000" list. | |
27321 | 193 *vim9-variable-arguments* *E1055* |
20241 | 194 Variable arguments are defined as the last argument, with a name and have a |
21825 | 195 list type, similar to TypeScript. For example, a list of numbers: > |
22171 | 196 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
|
197 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
|
198 ... |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
199 |
24272
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
200 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
|
201 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
|
202 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
|
203 should use its default value. Example: > |
25973 | 204 def MyFunc(one = 'one', last = 'last') |
24272
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
205 ... |
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
206 enddef |
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
207 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
|
208 < |
96e0b898d5b4
patch 8.2.2744: Vim9: no way to explicitly ignore an argument
Bram Moolenaar <Bram@vim.org>
parents:
24387
diff
changeset
|
209 *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
|
210 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
|
211 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
|
212 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
|
213 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
|
214 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
|
215 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
|
216 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
|
217 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
218 |
20241 | 219 Functions and variables are script-local by default ~ |
20856 | 220 *vim9-scopes* |
20115 | 221 When using `:function` or `:def` to specify a new function at the script level |
222 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
|
223 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
|
224 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
|
225 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
|
226 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
|
227 def s:ThisFunction() # script-local |
22171 | 228 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
|
229 def scriptname#function() # autoload |
27321 | 230 < *E1058* *E1075* |
22494
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
231 When using `:function` or `:def` to specify a nested function inside a `:def` |
26438 | 232 function and no namespace was given, this nested function is local to the code |
233 block it is defined in. In a `:def` function it is not possible to define a | |
234 script-local function. It is possible to define a global function by using | |
235 the "g:" prefix. | |
20115 | 236 |
237 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
|
238 search for the function: |
22565 | 239 - 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
|
240 - 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
|
241 |
24272
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
242 Since a script-local function reference can be used without "s:" the name must |
24278 | 243 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
|
244 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
|
245 "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
|
246 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
|
247 |
22500
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
248 In all cases the function must be defined before used. That is when it is |
22723 | 249 called, when `:defcompile` causes it to be compiled, or when code that calls |
250 it is being compiled (to figure out the return type). | |
20241 | 251 |
21676 | 252 The result is that functions and variables without a namespace can usually be |
20241 | 253 found in the script, either defined there or imported. Global functions and |
21676 | 254 variables could be defined anywhere (good luck finding out where!). |
27459 | 255 *E1102* |
21825 | 256 Global functions can still be defined and deleted at nearly any time. In |
20317 | 257 Vim9 script script-local functions are defined once when the script is sourced |
20552 | 258 and cannot be deleted or replaced. |
20115 | 259 |
23305 | 260 When compiling a function and a function call is encountered for a function |
261 that is not (yet) defined, the |FuncUndefined| autocommand is not triggered. | |
262 You can use an autoload function if needed, or call a legacy function and have | |
263 |FuncUndefined| triggered there. | |
264 | |
20115 | 265 |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
266 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
|
267 *vim9-reload* |
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
268 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
|
269 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
|
270 |
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
271 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
|
272 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
|
273 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
|
274 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
|
275 |
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
276 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
|
277 vim9script noclear |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
278 |
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
279 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
|
280 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
|
281 vim9script noclear |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
282 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
|
283 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
|
284 def g:SomeFunc() |
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
285 .... |
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
286 |
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
287 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
288 Variable declarations with :var, :final and :const ~ |
27459 | 289 *vim9-declaration* *:var* |
290 *E1017* *E1020* *E1054* *E1087* *E1108* *E1124* | |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
291 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
|
292 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
|
293 section. |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
294 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
295 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
|
296 vim9script |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
297 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
|
298 def SomeFunc() |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
299 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
|
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 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
|
302 ... |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
303 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
304 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
|
305 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
|
306 if cond |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
307 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
|
308 else |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
309 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
|
310 endif |
22171 | 311 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
|
312 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
313 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
|
314 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
|
315 if cond |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
316 inner = 5 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
317 else |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
318 inner = 0 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
319 endif |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
320 echo inner |
27459 | 321 < *E1025* *E1128* |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
322 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
|
323 used: > |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
324 { |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
325 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
|
326 ... |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
327 } |
22171 | 328 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
|
329 |
25402 | 330 This is especially useful in a user command: > |
331 | |
332 command -range Rename { | |
25619 | 333 var save = @a |
334 @a = 'some expression' | |
335 echo 'do something with ' .. @a | |
336 @a = save | |
337 } | |
25402 | 338 |
339 And with autocommands: > | |
340 | |
341 au BufWritePre *.go { | |
25619 | 342 var save = winsaveview() |
343 silent! exe ':%! some formatting command' | |
344 winrestview(save) | |
345 } | |
25402 | 346 |
347 Although using a :def function probably works better. | |
27459 | 348 *E1022* *E1103* *E1130* *E1131* *E1133* *E1134* |
22272
eb1f5f618c75
patch 8.2.1685: Vim9: cannot declare a constant value
Bram Moolenaar <Bram@vim.org>
parents:
22171
diff
changeset
|
349 Declaring a variable with a type but without an initializer will initialize to |
26755
ddaea8dcaff5
patch 8.2.3906: Vim9 help still contains "under development" warnings
Bram Moolenaar <Bram@vim.org>
parents:
26745
diff
changeset
|
350 false (for bool), empty (for string, list, dict, etc.) or zero (for number, |
ddaea8dcaff5
patch 8.2.3906: Vim9 help still contains "under development" warnings
Bram Moolenaar <Bram@vim.org>
parents:
26745
diff
changeset
|
351 any, etc.). This matters especially when using the "any" type, the value will |
ddaea8dcaff5
patch 8.2.3906: Vim9 help still contains "under development" warnings
Bram Moolenaar <Bram@vim.org>
parents:
26745
diff
changeset
|
352 default to the number zero. |
27321 | 353 *E1016* *E1052* *E1066* |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
354 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
|
355 without any command. The same for global, window, tab, buffer and Vim |
26769
30972227ac8d
patch 8.2.3913: help for expressions does not mention Vim9 syntax
Bram Moolenaar <Bram@vim.org>
parents:
26755
diff
changeset
|
356 variables, because they are not really declared. Those 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
|
357 with `:unlet`. |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
358 |
24272
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
359 `: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
|
360 instead. |
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
361 |
25619 | 362 The `exists()` and `exists_compiled()` functions do not work on local variables |
363 or arguments. | |
27321 | 364 *E1006* *E1041* |
24024 | 365 Variables, functions and function arguments cannot shadow previously defined |
366 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
|
367 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
|
368 |
24387 | 369 Global variables must be prefixed with "g:", also at the script level. > |
19968 | 370 vim9script |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
371 var script_local = 'text' |
21499 | 372 g:global = 'value' |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
373 var Funcref = g:ThatFunction |
19968 | 374 |
24387 | 375 Global functions must be prefixed with "g:" when defining them, but can be |
376 called without "g:". > | |
377 vim9script | |
378 def g:GlobalFunc(): string | |
379 return 'text' | |
380 enddef | |
381 echo GlobalFunc() | |
382 The "g:" prefix is not needed for auto-load functions. | |
383 | |
25619 | 384 *vim9-function-defined-later* |
385 Although global functions can be called without the "g:" prefix, they must | |
386 exist when compiled. By adding the "g:" prefix the function can be defined | |
387 later. Example: > | |
388 def CallPluginFunc() | |
389 if exists('g:loaded_plugin') | |
390 g:PluginFunc() | |
391 endif | |
392 enddef | |
393 | |
26873
be85735650f7
patch 8.2.3965: Vim9: no easy way to check if Vim9 script is supported
Bram Moolenaar <Bram@vim.org>
parents:
26769
diff
changeset
|
394 If you do it like this, you get an error at compile time that "PluginFunc" |
be85735650f7
patch 8.2.3965: Vim9: no easy way to check if Vim9 script is supported
Bram Moolenaar <Bram@vim.org>
parents:
26769
diff
changeset
|
395 does not exist, even when "g:loaded_plugin" does not exist: > |
25619 | 396 def CallPluginFunc() |
397 if exists('g:loaded_plugin') | |
398 PluginFunc() # Error - function not found | |
399 endif | |
400 enddef | |
401 | |
402 You can use exists_compiled() to avoid the error, but then the function would | |
403 not be called, even when "g:loaded_plugin" is defined later: > | |
404 def CallPluginFunc() | |
405 if exists_compiled('g:loaded_plugin') | |
406 PluginFunc() # Function may never be called | |
407 endif | |
408 enddef | |
409 | |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
410 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
|
411 used to repeat a `:substitute` command. |
24468 | 412 *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
|
413 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
|
414 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
|
415 [a, _, c] = theList |
24468 | 416 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
|
417 [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
|
418 |
78343859f42d
patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack
Bram Moolenaar <Bram@vim.org>
parents:
24408
diff
changeset
|
419 Declaring more than one variable at a time, using the unpack notation, is |
26346
8be6413a8e27
patch 8.2.3704: Vim9: cannot use a list declaration in a :def function
Bram Moolenaar <Bram@vim.org>
parents:
26304
diff
changeset
|
420 possible. Each variable can have a type or infer it from the value: > |
8be6413a8e27
patch 8.2.3704: Vim9: cannot use a list declaration in a :def function
Bram Moolenaar <Bram@vim.org>
parents:
26304
diff
changeset
|
421 var [v1: number, v2] = GetValues() |
8be6413a8e27
patch 8.2.3704: Vim9: cannot use a list declaration in a :def function
Bram Moolenaar <Bram@vim.org>
parents:
26304
diff
changeset
|
422 Use this only when there is a list with values, declaring one variable per |
8be6413a8e27
patch 8.2.3704: Vim9: cannot use a list declaration in a :def function
Bram Moolenaar <Bram@vim.org>
parents:
26304
diff
changeset
|
423 line is much easier to read and change later. |
24426
78343859f42d
patch 8.2.2753: Vim9: cannot ignore an item in assignment unpack
Bram Moolenaar <Bram@vim.org>
parents:
24408
diff
changeset
|
424 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
425 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
426 Constants ~ |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
427 *vim9-const* *vim9-final* |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
428 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
|
429 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
|
430 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
|
431 cannot be changed. In Vim9 we can use both. |
27321 | 432 *E1021* |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
433 `: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
|
434 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
|
435 Example: > |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
436 const myList = [1, 2] |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
437 myList = [3, 4] # Error! |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
438 myList[0] = 9 # Error! |
24024 | 439 myList->add(3) # Error! |
27459 | 440 < *:final* *E1125* |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
441 `: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
|
442 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
|
443 final myList = [1, 2] |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
444 myList = [3, 4] # Error! |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
445 myList[0] = 9 # OK |
24024 | 446 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
|
447 |
eb1f5f618c75
patch 8.2.1685: Vim9: cannot declare a constant value
Bram Moolenaar <Bram@vim.org>
parents:
22171
diff
changeset
|
448 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
|
449 |
eb1f5f618c75
patch 8.2.1685: Vim9: cannot declare a constant value
Bram Moolenaar <Bram@vim.org>
parents:
22171
diff
changeset
|
450 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
|
451 final females = ["Mary"] |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
452 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
|
453 NAMES[0] = ["Jack"] # Error! |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
454 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
|
455 NAMES[1] = ["Emma"] # Error! |
23573 | 456 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
|
457 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
458 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
459 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
|
460 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
461 Functions can be called without `:call`: > |
22171 | 462 writefile(lines, 'file') |
19303 | 463 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
|
464 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
465 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
|
466 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
|
467 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
|
468 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
|
469 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
|
470 [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
|
471 {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
|
472 "foobar"->Process() |
c7b2ce90c2de
patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit
Bram Moolenaar <Bram@vim.org>
parents:
21499
diff
changeset
|
473 ("foobar")->Process() |
c7b2ce90c2de
patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit
Bram Moolenaar <Bram@vim.org>
parents:
21499
diff
changeset
|
474 'foobar'->Process() |
c7b2ce90c2de
patch 8.2.1308: Vim9: accidentally using "x" causes Vim to exit
Bram Moolenaar <Bram@vim.org>
parents:
21499
diff
changeset
|
475 ('foobar')->Process() |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
476 |
21825 | 477 In the rare case there is ambiguity between a function name and an Ex command, |
21676 | 478 prepend ":" to make clear you want to use the Ex command. For example, there |
479 is both the `:substitute` command and the `substitute()` function. When the | |
480 line starts with `substitute(` this will use the function. Prepend a colon to | |
481 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
|
482 :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
|
483 |
25402 | 484 If the expression starts with "!" this is interpreted as a shell command, not |
485 negation of a condition. Thus this is a shell command: > | |
486 !shellCommand->something | |
25700 | 487 Put the expression in parentheses to use the "!" for negation: > |
25402 | 488 (!expression)->Method() |
489 | |
19556
ff5048b0ccfe
patch 8.2.0335: no completion for :disassemble
Bram Moolenaar <Bram@vim.org>
parents:
19523
diff
changeset
|
490 Note that while variables need to be defined before they can be used, |
21825 | 491 functions can be called before being defined. This is required to allow |
492 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
|
493 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
|
494 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
|
495 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
496 |
19968 | 497 Omitting function() ~ |
498 | |
499 A user defined function can be used as a function reference in an expression | |
500 without `function()`. The argument types and return type will then be checked. | |
501 The function must already have been defined. > | |
502 | |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
503 var Funcref = MyFunction |
19968 | 504 |
505 When using `function()` the resulting type is "func", a function with any | |
25161 | 506 number of arguments and any return type (including void). The function can be |
26708 | 507 defined later if the argument is in quotes. |
19968 | 508 |
509 | |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
510 Lambda using => instead of -> ~ |
24387 | 511 *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
|
512 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
|
513 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
|
514 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
|
515 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
|
516 |
c76240efdf02
patch 8.2.2204: Vim9: using -> both for method and lambda is confusing
Bram Moolenaar <Bram@vim.org>
parents:
23305
diff
changeset
|
517 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
|
518 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
|
519 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
|
520 |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
521 No line break is allowed in the arguments of a lambda up to and including the |
25056 | 522 "=>" (so that Vim can tell the difference between an expression in parentheses |
24911 | 523 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
|
524 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
|
525 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
|
526 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
|
527 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
|
528 => v > 0) |
23392
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
529 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
|
530 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
|
531 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
|
532 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
|
533 filter(list, (k, |
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
534 \ v) |
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
535 \ => 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
|
536 < *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
|
537 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
|
538 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
|
539 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
|
540 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
|
541 |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
|
542 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
|
543 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
|
544 |
24387 | 545 < *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
|
546 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
|
547 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
|
548 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
|
549 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
|
550 } |
24387 | 551 This can be useful for a timer, for example: > |
552 var count = 0 | |
553 var timer = timer_start(500, (_) => { | |
554 count += 1 | |
555 echom 'Handler called ' .. count | |
556 }, {repeat: 3}) | |
557 | |
24272
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
558 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
|
559 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
|
560 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
|
561 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
|
562 }) |
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
563 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
|
564 |
27321 | 565 *command-block* *E1026* |
26612
2586659245db
patch 8.2.3835: the inline-function example does not work
Bram Moolenaar <Bram@vim.org>
parents:
26591
diff
changeset
|
566 The block can also be used for defining a user command. Inside the block Vim9 |
2586659245db
patch 8.2.3835: the inline-function example does not work
Bram Moolenaar <Bram@vim.org>
parents:
26591
diff
changeset
|
567 syntax will be used. |
2586659245db
patch 8.2.3835: the inline-function example does not work
Bram Moolenaar <Bram@vim.org>
parents:
26591
diff
changeset
|
568 |
26591 | 569 If the statements include a dictionary, its closing bracket must not be |
570 written at the start of a line. Otherwise, it would be parsed as the end of | |
571 the block. This does not work: > | |
572 command NewCommand { | |
26612
2586659245db
patch 8.2.3835: the inline-function example does not work
Bram Moolenaar <Bram@vim.org>
parents:
26591
diff
changeset
|
573 g:mydict = { |
26591 | 574 'key': 'value', |
575 } # ERROR: will be recognized as the end of the block | |
576 } | |
577 Put the '}' after the last item to avoid this: > | |
578 command NewCommand { | |
26612
2586659245db
patch 8.2.3835: the inline-function example does not work
Bram Moolenaar <Bram@vim.org>
parents:
26591
diff
changeset
|
579 g:mydict = { |
26591 | 580 'key': 'value' } |
581 } | |
582 | |
24272
cabed216cc2f
patch 8.2.2677: Vim9: cannot use only some of the default arguments
Bram Moolenaar <Bram@vim.org>
parents:
24150
diff
changeset
|
583 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
|
584 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
|
585 "{". 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
|
586 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
|
587 |
23737 | 588 *vim9-curly* |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
589 To avoid the "{" of a dictionary literal to be recognized as a statement block |
24024 | 590 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
|
591 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
|
592 |
23737 | 593 Also when confused with the start of a command block: > |
594 ({ | |
595 key: value | |
596 })->method() | |
597 | |
23318
c76240efdf02
patch 8.2.2204: Vim9: using -> both for method and lambda is confusing
Bram Moolenaar <Bram@vim.org>
parents:
23305
diff
changeset
|
598 |
19999
844c7646f61b
patch 8.2.0555: Vim9: line continuation is not always needed
Bram Moolenaar <Bram@vim.org>
parents:
19968
diff
changeset
|
599 Automatic line continuation ~ |
27459 | 600 *vim9-line-continuation* *E1097* |
19999
844c7646f61b
patch 8.2.0555: Vim9: line continuation is not always needed
Bram Moolenaar <Bram@vim.org>
parents:
19968
diff
changeset
|
601 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
|
602 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
|
603 |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
|
604 var mylist = [ |
19999
844c7646f61b
patch 8.2.0555: Vim9: line continuation is not always needed
Bram Moolenaar <Bram@vim.org>
parents:
19968
diff
changeset
|
605 'one', |
844c7646f61b
patch 8.2.0555: Vim9: line continuation is not always needed
Bram Moolenaar <Bram@vim.org>
parents:
19968
diff
changeset
|
606 'two', |
844c7646f61b
patch 8.2.0555: Vim9: line continuation is not always needed
Bram Moolenaar <Bram@vim.org>
parents:
19968
diff
changeset
|
607 ] |
20011
628011800942
patch 8.2.0561: Vim9: cannot split function call in multiple lines
Bram Moolenaar <Bram@vim.org>
parents:
19999
diff
changeset
|
608 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
|
609 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
|
610 one: 1, |
628011800942
patch 8.2.0561: Vim9: cannot split function call in multiple lines
Bram Moolenaar <Bram@vim.org>
parents:
19999
diff
changeset
|
611 two: 2, |
628011800942
patch 8.2.0561: Vim9: cannot split function call in multiple lines
Bram Moolenaar <Bram@vim.org>
parents:
19999
diff
changeset
|
612 } |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
613 With a function call: > |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
614 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
|
615 arg1, |
628011800942
patch 8.2.0561: Vim9: cannot split function call in multiple lines
Bram Moolenaar <Bram@vim.org>
parents:
19999
diff
changeset
|
616 arg2 |
628011800942
patch 8.2.0561: Vim9: cannot split function call in multiple lines
Bram Moolenaar <Bram@vim.org>
parents:
19999
diff
changeset
|
617 ) |
628011800942
patch 8.2.0561: Vim9: cannot split function call in multiple lines
Bram Moolenaar <Bram@vim.org>
parents:
19999
diff
changeset
|
618 |
20982
bb49b5090a9c
patch 8.2.1042: Vim9: cannot put an operator on the next line
Bram Moolenaar <Bram@vim.org>
parents:
20965
diff
changeset
|
619 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
|
620 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
|
621 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
|
622 .. middle |
bb49b5090a9c
patch 8.2.1042: Vim9: cannot put an operator on the next line
Bram Moolenaar <Bram@vim.org>
parents:
20965
diff
changeset
|
623 .. end |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
624 var total = start + |
23573 | 625 end - |
20013
bf377a9ffccb
patch 8.2.0562: Vim9: cannot split an expression into multiple lines
Bram Moolenaar <Bram@vim.org>
parents:
20011
diff
changeset
|
626 correction |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
627 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
|
628 ? 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
|
629 : 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
|
630 |
21499 | 631 For a method call using "->" and a member using a dot, a line break is allowed |
632 before it: > | |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
633 var result = GetBuilder() |
20965 | 634 ->BuilderSetWidth(333) |
635 ->BuilderSetHeight(777) | |
636 ->BuilderBuild() | |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
637 var result = MyDict |
21499 | 638 .member |
20965 | 639 |
23392
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
640 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
|
641 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
|
642 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
|
643 | echo 'match' |
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
644 | endif |
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
645 |
25973 | 646 Note that this means that in heredoc the first line cannot start with a bar: > |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
647 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
|
648 | 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
|
649 END |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
650 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
|
651 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
|
652 set cpo+=C |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
653 var lines =<< trim END |
25973 | 654 | this works |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
655 END |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
656 set cpo-=C |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
657 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
|
658 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
|
659 |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
660 In places where line continuation with a backslash is still needed, such as |
25161 | 661 splitting up a long Ex command, comments can start with '#\ ': > |
662 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
|
663 \ start='foo' |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
664 #\ comment |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
665 \ end='bar' |
25161 | 666 Like with legacy script '"\ ' is used. This is also needed when line |
667 continuation is used without a backslash and a line starts with a bar: > | |
668 au CursorHold * echom 'BEFORE bar' | |
669 #\ some comment | |
670 | echom 'AFTER bar' | |
671 < | |
672 *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
|
673 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
|
674 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
|
675 add "start" and print: > |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
676 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
|
677 + print |
21250 | 678 Like this: > |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
679 var result = start + print |
21250 | 680 |
20982
bb49b5090a9c
patch 8.2.1042: Vim9: cannot put an operator on the next line
Bram Moolenaar <Bram@vim.org>
parents:
20965
diff
changeset
|
681 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
|
682 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
|
683 :+ print |
19999
844c7646f61b
patch 8.2.0555: Vim9: line continuation is not always needed
Bram Moolenaar <Bram@vim.org>
parents:
19968
diff
changeset
|
684 |
27321 | 685 After the range an Ex command must follow. Without the colon you can call a |
686 function without `:call`, but after a range you do need it: > | |
687 MyFunc() | |
688 :% call MyFunc() | |
689 | |
23047 | 690 Note that the colon is not required for the |+cmd| argument: > |
691 edit +6 fname | |
692 | |
20015
c001ee73519a
patch 8.2.0563: Vim9: cannot split a function line
Bram Moolenaar <Bram@vim.org>
parents:
20013
diff
changeset
|
693 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
|
694 arguments: > |
c001ee73519a
patch 8.2.0563: Vim9: cannot split a function line
Bram Moolenaar <Bram@vim.org>
parents:
20013
diff
changeset
|
695 def MyFunc( |
c001ee73519a
patch 8.2.0563: Vim9: cannot split a function line
Bram Moolenaar <Bram@vim.org>
parents:
20013
diff
changeset
|
696 text: string, |
c001ee73519a
patch 8.2.0563: Vim9: cannot split a function line
Bram Moolenaar <Bram@vim.org>
parents:
20013
diff
changeset
|
697 separator = '-' |
c001ee73519a
patch 8.2.0563: Vim9: cannot split a function line
Bram Moolenaar <Bram@vim.org>
parents:
20013
diff
changeset
|
698 ): string |
c001ee73519a
patch 8.2.0563: Vim9: cannot split a function line
Bram Moolenaar <Bram@vim.org>
parents:
20013
diff
changeset
|
699 |
23305 | 700 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
|
701 has been made stricter. E.g., because of the error in the first line, the |
23305 | 702 second line is seen as a separate command: > |
703 popup_create(some invalid expression, { | |
704 exit_cb: Func}) | |
705 Now "exit_cb: Func})" is actually a valid command: save any changes to the | |
706 file "_cb: Func})" and exit. To avoid this kind of mistake in Vim9 script | |
707 there must be white space between most command names and the argument. | |
27459 | 708 *E1144* |
23305 | 709 |
23666 | 710 However, the argument of a command that is a command won't be recognized. For |
711 example, after "windo echo expr" a line break inside "expr" will not be seen. | |
712 | |
23305 | 713 |
21250 | 714 Notes: |
715 - "enddef" cannot be used at the start of a continuation line, it ends the | |
716 current function. | |
717 - No line break is allowed in the LHS of an assignment. Specifically when | |
718 unpacking a list |:let-unpack|. This is OK: > | |
22171 | 719 [var1, var2] = |
21250 | 720 Func() |
721 < This does not work: > | |
22171 | 722 [var1, |
21250 | 723 var2] = |
724 Func() | |
725 - No line break is allowed in between arguments of an `:echo`, `:execute` and | |
726 similar commands. This is OK: > | |
22171 | 727 echo [1, |
21250 | 728 2] [3, |
729 4] | |
730 < This does not work: > | |
22171 | 731 echo [1, 2] |
21250 | 732 [3, 4] |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
733 - 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
|
734 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
|
735 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
|
736 |
24569 | 737 |
738 White space ~ | |
27459 | 739 *E1004* *E1068* *E1069* *E1074* *E1127* |
24569 | 740 Vim9 script enforces proper use of white space. This is no longer allowed: > |
741 var name=234 # Error! | |
742 var name= 234 # Error! | |
743 var name =234 # Error! | |
744 There must be white space before and after the "=": > | |
745 var name = 234 # OK | |
746 White space must also be put before the # that starts a comment after a | |
747 command: > | |
748 var name = 234# Error! | |
749 var name = 234 # OK | |
750 | |
751 White space is required around most operators. | |
752 | |
753 White space is required in a sublist (list slice) around the ":", except at | |
754 the start and end: > | |
755 otherlist = mylist[v : count] # v:count has a different meaning | |
756 otherlist = mylist[:] # make a copy of the List | |
757 otherlist = mylist[v :] | |
758 otherlist = mylist[: v] | |
759 | |
760 White space is not allowed: | |
761 - Between a function name and the "(": > | |
762 Func (arg) # Error! | |
763 Func | |
764 \ (arg) # Error! | |
765 Func | |
766 (arg) # Error! | |
767 Func(arg) # OK | |
768 Func( | |
769 arg) # OK | |
770 Func( | |
771 arg # OK | |
772 ) | |
773 | |
25700 | 774 White space is not allowed in a `:set` command between the option name and a |
775 following "&", "!", "<", "=", "+=", "-=" or "^=". | |
25402 | 776 |
24569 | 777 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
778 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
|
779 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
780 |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
|
781 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
782 |
22936
00b0275ffe7f
patch 8.2.2015: Vim9: literal dict #{} is not like any other language
Bram Moolenaar <Bram@vim.org>
parents:
22723
diff
changeset
|
783 Dictionary literals ~ |
27321 | 784 *vim9-literal-dict* *E1014* |
22936
00b0275ffe7f
patch 8.2.2015: Vim9: literal dict #{} is not like any other language
Bram Moolenaar <Bram@vim.org>
parents:
22723
diff
changeset
|
785 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
|
786 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
|
787 |
23088
285cde4b8d0e
patch 8.2.2090: Vim9: dict does not accept a key in quotes
Bram Moolenaar <Bram@vim.org>
parents:
23047
diff
changeset
|
788 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
|
789 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
|
790 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
|
791 |
23088
285cde4b8d0e
patch 8.2.2090: Vim9: dict does not accept a key in quotes
Bram Moolenaar <Bram@vim.org>
parents:
23047
diff
changeset
|
792 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
|
793 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
|
794 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
|
795 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
|
796 uses literal keys: > |
23666 | 797 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
|
798 |
23088
285cde4b8d0e
patch 8.2.2090: Vim9: dict does not accept a key in quotes
Bram Moolenaar <Bram@vim.org>
parents:
23047
diff
changeset
|
799 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
|
800 use another character, use a single or double quoted string: > |
23666 | 801 var dict = {'key with space': value} |
802 var dict = {"key\twith\ttabs": value} | |
803 var dict = {'': value} # empty key | |
27459 | 804 < *E1139* |
23088
285cde4b8d0e
patch 8.2.2090: Vim9: dict does not accept a key in quotes
Bram Moolenaar <Bram@vim.org>
parents:
23047
diff
changeset
|
805 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
|
806 like in JavaScript: > |
23666 | 807 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
|
808 |
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
|
809 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
|
810 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
|
811 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
|
812 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
|
813 {'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
|
814 |
22936
00b0275ffe7f
patch 8.2.2015: Vim9: literal dict #{} is not like any other language
Bram Moolenaar <Bram@vim.org>
parents:
22723
diff
changeset
|
815 |
23978
54b2aa1f0d42
patch 8.2.2531: Vim9: the :k command is obscure
Bram Moolenaar <Bram@vim.org>
parents:
23974
diff
changeset
|
816 No :xit, :t, :k, :append, :change or :insert ~ |
27459 | 817 *E1100* |
21584
d0c76ce48326
patch 8.2.1342: Vim9: accidentally using "t" gives a confusing error
Bram Moolenaar <Bram@vim.org>
parents:
21550
diff
changeset
|
818 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
|
819 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
|
820 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
|
821 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
|
822 |
19303 | 823 |
824 Comparators ~ | |
825 | |
826 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
|
827 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
828 |
24569 | 829 Abort after error ~ |
830 | |
831 In legacy script, when an error is encountered, Vim continues to execute | |
832 following lines. This can lead to a long sequence of errors and need to type | |
833 CTRL-C to stop it. In Vim9 script execution of commands stops at the first | |
834 error. Example: > | |
835 vim9script | |
836 var x = does-not-exist | |
837 echo 'not executed' | |
838 | |
839 | |
23666 | 840 For loop ~ |
841 | |
26438 | 842 The loop variable must not be declared yet: > |
26304 | 843 var i = 1 |
844 for i in [1, 2, 3] # Error! | |
845 | |
26438 | 846 It is possible to use a global variable though: > |
847 g:i = 1 | |
848 for g:i in [1, 2, 3] | |
849 echo g:i | |
850 endfor | |
851 | |
23666 | 852 Legacy Vim script has some tricks to make a for loop over a list handle |
853 deleting items at the current or previous item. In Vim9 script it just uses | |
854 the index, if items are deleted then items in the list will be skipped. | |
855 Example legacy script: > | |
856 let l = [1, 2, 3, 4] | |
857 for i in l | |
858 echo i | |
859 call remove(l, index(l, i)) | |
860 endfor | |
861 Would echo: | |
862 1 | |
863 2 | |
864 3 | |
865 4 | |
866 In compiled Vim9 script you get: | |
867 1 | |
868 3 | |
869 Generally, you should not change the list that is iterated over. Make a copy | |
870 first if needed. | |
871 | |
872 | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
873 Conditions and expressions ~ |
27321 | 874 *vim9-boolean* |
22500
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
875 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
|
876 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
|
877 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
|
878 0 falsy falsy |
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
879 1 truthy truthy |
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
880 99 truthy Error! |
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
881 "0" falsy Error! |
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
882 "99" truthy Error! |
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
883 "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
|
884 |
22500
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
885 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
|
886 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
|
887 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
|
888 |
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
889 type truthy when ~ |
23466 | 890 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
|
891 number non-zero |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
892 float non-zero |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
893 string non-empty |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
894 blob non-empty |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
895 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
|
896 dictionary non-empty (different from JavaScript) |
19968 | 897 func when there is a function name |
23466 | 898 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
|
899 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
|
900 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
|
901 class when not NULL |
23466 | 902 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
|
903 |
22494
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
904 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
|
905 one: > |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
906 1 || false == true |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
907 0 || 1 == true |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
908 0 || false == false |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
909 1 && true == true |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
910 0 && 1 == false |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
911 8 || 0 Error! |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
912 'yes' && 0 Error! |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
913 [] || 99 Error! |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
914 |
22494
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
915 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
|
916 result is a boolean. "!!" can be used to turn any value into boolean: > |
23573 | 917 !'yes' == false |
22500
ef8a3177edc1
patch 8.2.1798: Vim9: trinary operator condition is too permissive
Bram Moolenaar <Bram@vim.org>
parents:
22494
diff
changeset
|
918 !![] == false |
23573 | 919 !![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
|
920 |
4c21f7f6f9e3
patch 8.2.1795: Vim9: operators && and || have a confusing result
Bram Moolenaar <Bram@vim.org>
parents:
22441
diff
changeset
|
921 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
|
922 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
|
923 'hello ' .. 123 == 'hello 123' |
23466 | 924 '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
|
925 |
26769
30972227ac8d
patch 8.2.3913: help for expressions does not mention Vim9 syntax
Bram Moolenaar <Bram@vim.org>
parents:
26755
diff
changeset
|
926 Simple types are Number, Float, Special and Bool. For other types |string()| |
30972227ac8d
patch 8.2.3913: help for expressions does not mention Vim9 syntax
Bram Moolenaar <Bram@vim.org>
parents:
26755
diff
changeset
|
927 should be used. |
27321 | 928 *false* *true* *null* *E1034* |
23497
2247a2ce3630
patch 8.2.2291: Vim9: cannot use "null" for v:null
Bram Moolenaar <Bram@vim.org>
parents:
23466
diff
changeset
|
929 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
|
930 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
|
931 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
|
932 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
|
933 |
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
|
934 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
|
935 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
|
936 Example: > |
21825 | 937 echo 'bár'[1] |
938 In legacy script this results in the character 0xc3 (an illegal byte), in Vim9 | |
939 script this results in the string 'á'. | |
23573 | 940 A negative index is counting from the end, "[-1]" is the last character. |
23666 | 941 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
|
942 To count composing characters separately use |strcharpart()|. |
23573 | 943 If the index is out of range then an empty string results. |
944 | |
945 In legacy script "++var" and "--var" would be silently accepted and have no | |
946 effect. This is an error in Vim9 script. | |
947 | |
948 Numbers starting with zero are not considered to be octal, only numbers | |
949 starting with "0o" are octal: "0o744". |scriptversion-4| | |
21825 | 950 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
951 |
21093 | 952 What to watch out for ~ |
953 *vim9-gotchas* | |
954 Vim9 was designed to be closer to often used programming languages, but at the | |
955 same time tries to support the legacy Vim commands. Some compromises had to | |
956 be made. Here is a summary of what might be unexpected. | |
957 | |
958 Ex command ranges need to be prefixed with a colon. > | |
23666 | 959 -> legacy Vim: shifts the previous line to the right |
960 ->func() Vim9: method call in a continuation line | |
961 :-> Vim9: shifts the previous line to the right | |
21093 | 962 |
23666 | 963 %s/a/b legacy Vim: substitute on all lines |
21093 | 964 x = alongname |
23666 | 965 % another Vim9: modulo operator in a continuation line |
966 :%s/a/b Vim9: substitute on all lines | |
967 't legacy Vim: jump to mark t | |
968 'text'->func() Vim9: method call | |
969 :'t Vim9: jump to mark t | |
21093 | 970 |
21676 | 971 Some Ex commands can be confused with assignments in Vim9 script: > |
23666 | 972 g:name = value # assignment |
25939
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
973 :g:pattern:cmd # :global command |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
974 |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
975 To avoid confusion between a `:global` or `:substitute` command and an |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
976 expression or assignment, a few separators cannot be used when these commands |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
977 are abbreviated to a single character: ':', '-' and '.'. > |
23666 | 978 g:pattern:cmd # invalid command - ERROR |
25939
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
979 s:pattern:repl # invalid command - ERROR |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
980 g-pattern-cmd # invalid command - ERROR |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
981 s-pattern-repl # invalid command - ERROR |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
982 g.pattern.cmd # invalid command - ERROR |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
983 s.pattern.repl # invalid command - ERROR |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
984 |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
985 Also, there cannot be a space between the command and the separator: > |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
986 g /pattern/cmd # invalid command - ERROR |
377a7686a52f
patch 8.2.3503: Vim9: using g:pat:cmd is confusing
Bram Moolenaar <Bram@vim.org>
parents:
25836
diff
changeset
|
987 s /pattern/repl # invalid command - ERROR |
21676 | 988 |
21093 | 989 Functions defined with `:def` compile the whole function. Legacy functions |
990 can bail out, and the following lines are not parsed: > | |
991 func Maybe() | |
992 if !has('feature') | |
993 return | |
994 endif | |
995 use-feature | |
996 endfunc | |
997 Vim9 functions are compiled as a whole: > | |
998 def Maybe() | |
999 if !has('feature') | |
1000 return | |
1001 endif | |
23573 | 1002 use-feature # May give a compilation error |
21093 | 1003 enddef |
1004 For a workaround, split it in two functions: > | |
1005 func Maybe() | |
1006 if has('feature') | |
23666 | 1007 call MaybeInner() |
21093 | 1008 endif |
1009 endfunc | |
1010 if has('feature') | |
1011 def MaybeInner() | |
1012 use-feature | |
1013 enddef | |
1014 endif | |
22171 | 1015 Or put the unsupported code inside an `if` with a constant expression that |
21991 | 1016 evaluates to false: > |
1017 def Maybe() | |
1018 if has('feature') | |
1019 use-feature | |
1020 endif | |
1021 enddef | |
25619 | 1022 The `exists_compiled()` function can also be used for this. |
1023 *vim9-user-command* | |
23666 | 1024 Another side effect of compiling a function is that the presence of a user |
23573 | 1025 command is checked at compile time. If the user command is defined later an |
1026 error will result. This works: > | |
1027 command -nargs=1 MyCommand echom <q-args> | |
1028 def Works() | |
1029 MyCommand 123 | |
1030 enddef | |
1031 This will give an error for "MyCommand" not being defined: > | |
1032 def Works() | |
1033 command -nargs=1 MyCommand echom <q-args> | |
1034 MyCommand 123 | |
1035 enddef | |
1036 A workaround is to invoke the command indirectly with `:execute`: > | |
1037 def Works() | |
1038 command -nargs=1 MyCommand echom <q-args> | |
1039 execute 'MyCommand 123' | |
1040 enddef | |
1041 | |
21991 | 1042 Note that for unrecognized commands there is no check for "|" and a following |
1043 command. This will give an error for missing `endif`: > | |
1044 def Maybe() | |
1045 if has('feature') | use-feature | endif | |
1046 enddef | |
21093 | 1047 |
23305 | 1048 Other differences ~ |
1049 | |
1050 Patterns are used like 'magic' is set, unless explicitly overruled. | |
1051 The 'edcompatible' option value is not used. | |
1052 The 'gdefault' option value is not used. | |
1053 | |
24387 | 1054 You may also find this wiki useful. It was written by an early adopter of |
24103 | 1055 Vim9 script: https://github.com/lacygoill/wiki/blob/master/vim/vim9.md |
23305 | 1056 |
25056 | 1057 *:++* *:--* |
1058 The ++ and -- commands have been added. They are very similar to adding or | |
1059 subtracting one: > | |
1060 ++var | |
1061 var += 1 | |
1062 --var | |
1063 var -= 1 | |
1064 | |
1065 Using ++var or --var in an expression is not supported yet. | |
1066 | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1067 ============================================================================== |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1068 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1069 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
|
1070 |
27321 | 1071 *:def* *E1028* |
21825 | 1072 :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
|
1073 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
|
1074 the function follows in the next lines, until the |
27321 | 1075 matching `:enddef`. *E1073* |
1076 *E1011* | |
1077 The {name} must be less than 100 bytes long. | |
1078 *E1003* *E1027* *E1056* *E1059* | |
1079 The type of value used with `:return` must match | |
1080 {return-type}. When {return-type} is omitted or is | |
1081 "void" the function is not expected to return | |
1082 anything. | |
27459 | 1083 *E1077* *E1123* |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1084 {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
|
1085 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
|
1086 {name}: {type} |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1087 {name} = {value} |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1088 {name}: {type} = {value} |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1089 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
|
1090 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
|
1091 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
|
1092 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
|
1093 |
20856 | 1094 The function will be compiled into instructions when |
21499 | 1095 called, or when `:disassemble` or `:defcompile` is |
1096 used. Syntax and type errors will be produced at that | |
1097 time. | |
20856 | 1098 |
21499 | 1099 It is possible to nest `:def` inside another `:def` or |
1100 `:function` up to about 50 levels deep. | |
27459 | 1101 *E1117* |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1102 [!] 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
|
1103 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
|
1104 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
|
1105 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
|
1106 |
27321 | 1107 *:enddef* *E1057* |
21499 | 1108 :enddef End of a function defined with `:def`. It should be on |
1109 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
|
1110 |
24387 | 1111 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
|
1112 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
|
1113 |
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
|
1114 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
|
1115 variables can be accessed without the "s:" prefix. They must be defined |
20856 | 1116 before the function is compiled. If the script the function is defined in is |
1117 legacy script, then script-local variables must be accessed with the "s:" | |
24387 | 1118 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
|
1119 |
20552 | 1120 *:defc* *:defcompile* |
1121 :defc[ompile] Compile functions defined in the current script that | |
1122 were not compiled yet. | |
1123 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
|
1124 |
19404 | 1125 *:disa* *:disassemble* |
1126 :disa[ssemble] {func} Show the instructions generated for {func}. | |
27321 | 1127 This is for debugging and testing. *E1061* |
19556
ff5048b0ccfe
patch 8.2.0335: no completion for :disassemble
Bram Moolenaar <Bram@vim.org>
parents:
19523
diff
changeset
|
1128 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
|
1129 can prepend "s:" to find script-local functions. |
19404 | 1130 |
24911 | 1131 :disa[ssemble] profile {func} |
1132 Like `:disassemble` but with the instructions used for | |
23737 | 1133 profiling. |
1134 | |
24911 | 1135 :disa[ssemble] debug {func} |
1136 Like `:disassemble` but with the instructions used for | |
1137 debugging. | |
1138 | |
21250 | 1139 Limitations ~ |
1140 | |
1141 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
|
1142 def MapList(): list<string> |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1143 var list = ['aa', 'bb', 'cc', 'dd'] |
21250 | 1144 return range(1, 2)->map('list[v:val]') |
1145 enddef | |
1146 | |
1147 The map argument is a string expression, which is evaluated without the | |
1148 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
|
1149 def MapList(): list<string> |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1150 var list = ['aa', 'bb', 'cc', 'dd'] |
25973 | 1151 return range(1, 2)->map((_, v) => list[v]) |
21250 | 1152 enddef |
1153 | |
26358
80b555c4aed0
patch 8.2.3710: Vim9: backtick expression expanded for :global
Bram Moolenaar <Bram@vim.org>
parents:
26346
diff
changeset
|
1154 For commands that are not compiled, such as `:edit`, backtick expansion can be |
80b555c4aed0
patch 8.2.3710: Vim9: backtick expression expanded for :global
Bram Moolenaar <Bram@vim.org>
parents:
26346
diff
changeset
|
1155 used and it can use the local scope. Example: > |
23358
b3142fc0a414
patch 8.2.2222: Vim9: cannot keep script variables when reloading
Bram Moolenaar <Bram@vim.org>
parents:
23318
diff
changeset
|
1156 def Replace() |
26358
80b555c4aed0
patch 8.2.3710: Vim9: backtick expression expanded for :global
Bram Moolenaar <Bram@vim.org>
parents:
26346
diff
changeset
|
1157 var fname = 'blah.txt' |
80b555c4aed0
patch 8.2.3710: Vim9: backtick expression expanded for :global
Bram Moolenaar <Bram@vim.org>
parents:
26346
diff
changeset
|
1158 edit `=fname` |
25402 | 1159 enddef |
1160 | |
24278 | 1161 Closures defined in a loop will share the same context. For example: > |
1162 var flist: list<func> | |
25402 | 1163 for i in range(5) |
24278 | 1164 var inloop = i |
1165 flist[i] = () => inloop | |
1166 endfor | |
25402 | 1167 echo range(5)->map((i, _) => flist[i]()) |
1168 # Result: [4, 4, 4, 4, 4] | |
24278 | 1169 |
1170 The "inloop" variable will exist only once, all closures put in the list refer | |
25402 | 1171 to the same instance, which in the end will have the value 4. This is |
1172 efficient, also when looping many times. If you do want a separate context | |
1173 for each closure call a function to define it: > | |
1174 def GetClosure(i: number): func | |
1175 var infunc = i | |
1176 return () => infunc | |
24278 | 1177 enddef |
1178 | |
1179 var flist: list<func> | |
25402 | 1180 for i in range(5) |
1181 flist[i] = GetClosure(i) | |
24278 | 1182 endfor |
25402 | 1183 echo range(5)->map((i, _) => flist[i]()) |
1184 # Result: [0, 1, 2, 3, 4] | |
24278 | 1185 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1186 ============================================================================== |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1187 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1188 4. Types *vim9-types* |
27321 | 1189 *E1008* *E1009* *E1010* *E1012* |
1190 *E1013* *E1029* *E1030* | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1191 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
|
1192 bool |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1193 number |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1194 float |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1195 string |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1196 blob |
19904
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1197 list<{type}> |
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1198 dict<{type}> |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1199 job |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1200 channel |
19646 | 1201 func |
19968 | 1202 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
|
1203 func({type}, ...) |
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1204 func({type}, ...): {type} |
27321 | 1205 void |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1206 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1207 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
|
1208 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
|
1209 |
25161 | 1210 These types can be used in declarations, but no simple value will actually |
27321 | 1211 have the "void" type. Trying to use a void (e.g. a function without a |
1212 return value) results in error *E1031* . | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1213 |
19904
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1214 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
|
1215 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
|
1216 memory. |
27321 | 1217 *E1005* *E1007* |
19904
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1218 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
|
1219 func any kind of function reference, no type |
19968 | 1220 checking for arguments or return value |
25161 | 1221 func: void any number and type of arguments, no return |
1222 value | |
19904
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1223 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
|
1224 return type |
25161 | 1225 |
1226 func() function with no argument, does not return a | |
1227 value | |
1228 func(): void same | |
1229 func(): {type} function with no argument and return type | |
1230 | |
19968 | 1231 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
|
1232 a value |
19968 | 1233 func({type}): {type} function with argument type and return type |
1234 func(?{type}) function with type of optional argument, does | |
1235 not return a value | |
1236 func(...{type}) function with type of variable number of | |
1237 arguments, does not return a value | |
1238 func({type}, ?{type}, ...{type}): {type} | |
1239 function with: | |
1240 - type of mandatory argument | |
1241 - type of optional argument | |
1242 - type of variable number of arguments | |
1243 - 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
|
1244 |
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1245 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
|
1246 |
bd4f91762d0f
patch 8.2.0508: Vim9: func and partial types not done yet
Bram Moolenaar <Bram@vim.org>
parents:
19646
diff
changeset
|
1247 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
|
1248 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
|
1249 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
|
1250 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1251 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
|
1252 :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
|
1253 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
|
1254 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
|
1255 {not implemented yet} |
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 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
|
1258 :class MyClass |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1259 :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
|
1260 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1261 :interface MyInterface |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1262 :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
|
1263 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1264 :class MyTemplate<Targ> |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1265 :var mine: MyTemplate<number> |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1266 :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
|
1267 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1268 :class MyInterface<Targ> |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1269 :var mine: MyInterface<number> |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1270 :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
|
1271 {not implemented yet} |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1272 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1273 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1274 Variable types and type casting ~ |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1275 *variable-types* |
21717
ef3b31d510d2
patch 8.2.1408: Vim9: type casting not supported
Bram Moolenaar <Bram@vim.org>
parents:
21715
diff
changeset
|
1276 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
|
1277 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
|
1278 |
ef3b31d510d2
patch 8.2.1408: Vim9: type casting not supported
Bram Moolenaar <Bram@vim.org>
parents:
21715
diff
changeset
|
1279 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
|
1280 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
|
1281 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
|
1282 |
ef3b31d510d2
patch 8.2.1408: Vim9: type casting not supported
Bram Moolenaar <Bram@vim.org>
parents:
21715
diff
changeset
|
1283 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
|
1284 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
|
1285 var l: list<number> = [1, g:two] |
23305 | 1286 At compile time Vim doesn't know the type of "g:two" and the expression type |
1287 becomes list<any>. An instruction is generated to check the list type before | |
1288 doing the assignment, which is a bit inefficient. | |
27459 | 1289 *type-casting* *E1104* |
23305 | 1290 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
|
1291 var l: list<number> = [1, <number>g:two] |
23305 | 1292 The compiled code will then only check that "g:two" is a number and give an |
1293 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
|
1294 |
ef3b31d510d2
patch 8.2.1408: Vim9: type casting not supported
Bram Moolenaar <Bram@vim.org>
parents:
21715
diff
changeset
|
1295 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
|
1296 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
|
1297 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
|
1298 |
ef3b31d510d2
patch 8.2.1408: Vim9: type casting not supported
Bram Moolenaar <Bram@vim.org>
parents:
21715
diff
changeset
|
1299 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
|
1300 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
|
1301 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
|
1302 string to a number. |
ef3b31d510d2
patch 8.2.1408: Vim9: type casting not supported
Bram Moolenaar <Bram@vim.org>
parents:
21715
diff
changeset
|
1303 |
ef3b31d510d2
patch 8.2.1408: Vim9: type casting not supported
Bram Moolenaar <Bram@vim.org>
parents:
21715
diff
changeset
|
1304 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1305 Type inference ~ |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1306 *type-inference* |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1307 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
|
1308 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
|
1309 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
|
1310 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
|
1311 |
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
|
1312 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
|
1313 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
|
1314 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
|
1315 [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
|
1316 ['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
|
1317 [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
|
1318 |
25161 | 1319 The common type of function references, if they do not all have the same |
1320 number of arguments, uses "(...)" to indicate the number of arguments is not | |
1321 specified. For example: > | |
1322 def Foo(x: bool) | |
1323 enddef | |
1324 def Bar(x: bool, y: bool) | |
1325 enddef | |
1326 var funclist = [Foo, Bar] | |
1327 echo funclist->typename() | |
1328 Results in: | |
1329 list<func(...)> | |
1330 | |
24387 | 1331 For script-local variables in Vim9 script the type is checked, also when the |
1332 variable was declared in a legacy function. | |
1333 | |
27459 | 1334 When a type has been declared this is attached to a list or string. When |
1335 later some expression attempts to change the type an error will be given: > | |
1336 var ll: list<number> = [1, 2, 3] | |
1337 ll->extend('x') # Error, 'x' is not a number | |
1338 | |
1339 If the type is inferred then the type is allowed to change: > | |
1340 [1, 2, 3]->extend('x') # result: [1, 2, 3, 'x'] | |
1341 | |
21991 | 1342 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1343 Stricter type checking ~ |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1344 *type-checking* |
21991 | 1345 In legacy Vim script, where a number was expected, a string would be |
1346 automatically converted to a number. This was convenient for an actual number | |
24387 | 1347 such as "123", but leads to unexpected problems (and no error message) if the |
21991 | 1348 string doesn't start with a number. Quite often this leads to hard-to-find |
1349 bugs. | |
1350 | |
1351 In Vim9 script this has been made stricter. In most places it works just as | |
22171 | 1352 before, if the value used matches the expected type. There will sometimes be |
1353 an error, thus breaking backwards compatibility. For example: | |
21991 | 1354 - Using a number other than 0 or 1 where a boolean is expected. *E1023* |
25161 | 1355 - Using a string value when setting a number option. |
27459 | 1356 - Using a number where a string is expected. *E1024* *E1105* |
21991 | 1357 |
25973 | 1358 One consequence is that the item type of a list or dict given to |map()| must |
24024 | 1359 not change. This will give an error in Vim9 script: > |
25973 | 1360 echo map([1, 2, 3], (i, v) => 'item ' .. i) |
24024 | 1361 E1012: Type mismatch; expected number but got string |
25973 | 1362 Instead use |mapnew()|: > |
1363 echo mapnew([1, 2, 3], (i, v) => 'item ' .. i) | |
25161 | 1364 ['item 0', 'item 1', 'item 2'] |
1365 | |
1366 If the item type was determined to be "any" it can change to a more specific | |
25973 | 1367 type. E.g. when a list of mixed types gets changed to a list of strings: > |
25161 | 1368 var mylist = [1, 2.0, '3'] |
1369 # typename(mylist) == "list<any>" | |
1370 map(mylist, (i, v) => 'item ' .. i) | |
1371 # typename(mylist) == "list<string>", no error | |
1372 | |
24024 | 1373 Same for |extend()|, use |extendnew()| instead, and for |flatten()|, use |
1374 |flattennew()| instead. | |
23573 | 1375 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1376 ============================================================================== |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1377 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1378 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
|
1379 *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
|
1380 |
27162 | 1381 A Vim9 script can be written to be imported. This means that some items are |
1382 intentionally exported, made available to other scripts. When the exporting | |
1383 script is imported in another script, these exported items can then be used in | |
1384 that script. All the other items remain script-local in the exporting script | |
1385 and cannot be accessed by the importing script. | |
27036 | 1386 |
1387 This mechanism exists for writing a script that can be sourced (imported) by | |
1388 other scripts, while making sure these other scripts only have access to what | |
1389 you want them to. This also avoids using the global namespace, which has a | |
1390 risc of name collisions. For example when you have two plugins with similar | |
1391 functionality. | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1392 |
27162 | 1393 You can cheat by using the global namespace explicitly. That should be done |
1394 only for things that really are global. | |
21991 | 1395 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1396 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1397 Namespace ~ |
23392
517fca70e084
patch 8.2.2239: Vim9: concatenating lines with backslash is inconvenient
Bram Moolenaar <Bram@vim.org>
parents:
23360
diff
changeset
|
1398 *vim9-namespace* |
19303 | 1399 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
|
1400 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
|
1401 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
|
1402 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
|
1403 vim9script |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1404 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
|
1405 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
|
1406 be available as `g:myvar` from any other script and function. |
27459 | 1407 *E1101* |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1408 The variables at the file level are very much like the script-local "s:" |
20115 | 1409 variables in legacy Vim script, but the "s:" is omitted. And they cannot be |
1410 deleted. | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1411 |
20115 | 1412 In Vim9 script the global "g:" namespace can still be used as before. And the |
1413 "w:", "b:" and "t:" namespaces. These have in common that variables are not | |
1414 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
|
1415 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1416 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
|
1417 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
|
1418 :set cpo&vim |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1419 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
|
1420 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
|
1421 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
|
1422 original value to get the same effect. The order of flags may change. |
26745
dcd1c244e332
patch 8.2.3901: Vim9: Cannot set 'cpo' in main .vimrc if using Vim9 script
Bram Moolenaar <Bram@vim.org>
parents:
26708
diff
changeset
|
1423 In the |vimrc| file sourced on startup this does not happen. |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1424 |
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
|
1425 *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
|
1426 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
|
1427 " 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
|
1428 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
|
1429 " 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
|
1430 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
|
1431 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
|
1432 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
|
1433 # 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
|
1434 This allows for writing a script that takes advantage of the Vim9 script |
24024 | 1435 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
|
1436 |
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
|
1437 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
|
1438 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
|
1439 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
|
1440 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
|
1441 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
|
1442 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1443 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1444 Export ~ |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1445 *:export* *:exp* |
21499 | 1446 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
|
1447 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
|
1448 export var someValue = ... |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1449 export final someValue = ... |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1450 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
|
1451 export def MyFunc() ... |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1452 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
|
1453 export interface MyClass ... |
27321 | 1454 < *E1043* *E1044* |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1455 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
|
1456 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
|
1457 |
20856 | 1458 *E1042* |
1459 `: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
|
1460 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1461 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1462 Import ~ |
27321 | 1463 *:import* *:imp* *E1094* *E1047* |
1464 *E1048* *E1049* *E1053* *E1071* | |
26980
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1465 The exported items can be imported in another Vim9 script: > |
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1466 import "myscript.vim" |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1467 |
26980
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1468 This makes each item available as "myscript.item". |
27321 | 1469 *:import-as* |
26980
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1470 In case the name is long or ambiguous, another name can be specified: > |
27036 | 1471 import "thatscript.vim" as that |
27321 | 1472 < *E1060* |
27036 | 1473 Then you can use "that.EXPORTED_CONST", "that.someValue", etc. You are free |
1474 to choose the name "that". Use something that will be recognized as referring | |
27459 | 1475 to the imported script. Avoid command names, command modifiers and builtin |
1476 function names, because the name will shadow them. | |
1477 If the name starts with a capital letter it can also shadow global user | |
1478 commands and functions. Also, you cannot use the name for something else in | |
1479 the script, such as a function or variable name. | |
26980
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1480 |
27036 | 1481 In case the dot in the name is undesired, a local reference can be made for a |
1482 function: > | |
1483 var LongFunc = that.LongFuncName | |
26980
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1484 |
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1485 This also works for constants: > |
27036 | 1486 const MAXLEN = that.MAX_LEN_OF_NAME |
26980
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1487 |
27036 | 1488 This does not work for variables, since the value would be copied once and |
1489 when changing the variable the copy will change, not the original variable. | |
1490 You will need to use the full name, with the dot. | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1491 |
27321 | 1492 The full syntax of the command is: |
1493 import {filename} [as {name}] | |
1494 Where {filename} is an expression that must evaluate to a string. Without the | |
1495 "as {name}" part it must end in ".vim". {name} must consist of letters, | |
1496 digits and '_', like |internal-variables|. | |
1497 | |
22171 | 1498 `:import` can also be used in legacy Vim script. The imported items still |
1499 become script-local, even when the "s:" prefix is not given. | |
1500 | |
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
|
1501 `: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
|
1502 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
|
1503 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1504 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
|
1505 - 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
|
1506 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
|
1507 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
|
1508 - An absolute path, starting with "/" on Unix or "D:/" on MS-Windows. This |
22723 | 1509 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
|
1510 - 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
|
1511 "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
|
1512 longer and unique, to avoid loading the wrong file. |
25619 | 1513 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
|
1514 |
27036 | 1515 If the name does not end in ".vim" then the use of "as name" is required. |
1516 | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1517 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
|
1518 next time the same script is imported. It will not be read again. |
26980
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1519 |
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1520 It is not allowed to import the same script twice, also when using two |
8796f1384750
patch 8.2.4019: Vim9: import mechanism is too complicated
Bram Moolenaar <Bram@vim.org>
parents:
26873
diff
changeset
|
1521 different "as" names. |
27036 | 1522 |
1523 When using the imported name the dot and the item name must be in the same | |
1524 line, there can be no line break: > | |
1525 echo that. | |
1526 name # Error! | |
1527 echo that | |
1528 .name # Error! | |
1529 < *:import-cycle* | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1530 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
|
1531 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
|
1532 `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
|
1533 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
|
1534 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1535 |
27162 | 1536 Importing an autoload script ~ |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1537 *vim9-autoload* |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1538 For optimal startup speed, loading scripts should be postponed until they are |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1539 actually needed. Using the autoload mechanism is recommended: |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1540 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1541 1. In the plugin define user commands, functions and/or mappings that refer to |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1542 items imported from an autoload script. > |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1543 import autoload 'for/search.vim' |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1544 command -nargs=1 SearchForStuff search.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
|
1545 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1546 < This goes in .../plugin/anyname.vim. "anyname.vim" can be freely chosen. |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1547 The "SearchForStuff" command is now available to the user. |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1548 |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1549 The "autoload" argument to `:import` means that the script is not loaded |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1550 until one of the items is actually used. The script will be found under |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1551 the "autoload" directory in 'runtimepath' instead of the "import" |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1552 directory. |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1553 |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1554 2. In the autoload script put the bulk of the code. > |
27215
5b54f413d132
patch 8.2.4136: Vim9: the "autoload" argument of ":vim9script" is not useful
Bram Moolenaar <Bram@vim.org>
parents:
27162
diff
changeset
|
1555 vim9script |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1556 export def Stuff(arg: string) |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1557 ... |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1558 |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1559 < This goes in .../autoload/for/search.vim. |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1560 |
27215
5b54f413d132
patch 8.2.4136: Vim9: the "autoload" argument of ":vim9script" is not useful
Bram Moolenaar <Bram@vim.org>
parents:
27162
diff
changeset
|
1561 Putting the "search.vim" script under the "/autoload/for/" directory has |
5b54f413d132
patch 8.2.4136: Vim9: the "autoload" argument of ":vim9script" is not useful
Bram Moolenaar <Bram@vim.org>
parents:
27162
diff
changeset
|
1562 the effect that "for#search#" will be prefixed to every exported item. The |
5b54f413d132
patch 8.2.4136: Vim9: the "autoload" argument of ":vim9script" is not useful
Bram Moolenaar <Bram@vim.org>
parents:
27162
diff
changeset
|
1563 prefix is obtained from the file name, as you would to manually in a |
5b54f413d132
patch 8.2.4136: Vim9: the "autoload" argument of ":vim9script" is not useful
Bram Moolenaar <Bram@vim.org>
parents:
27162
diff
changeset
|
1564 legacy autoload script. Thus the exported function can be found with |
5b54f413d132
patch 8.2.4136: Vim9: the "autoload" argument of ":vim9script" is not useful
Bram Moolenaar <Bram@vim.org>
parents:
27162
diff
changeset
|
1565 "for#search#Stuff", but you would normally use `import autoload` and not |
5b54f413d132
patch 8.2.4136: Vim9: the "autoload" argument of ":vim9script" is not useful
Bram Moolenaar <Bram@vim.org>
parents:
27162
diff
changeset
|
1566 use the prefix. |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1567 |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1568 You can split up the functionality and import other scripts from the |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1569 autoload script as you like. This way you can share code between plugins. |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1570 |
27162 | 1571 For defining a mapping that uses the imported autoload script the special key |
1572 |<ScriptCmd>| is useful. It allows for a command in a mapping to use the | |
1573 script context of where the mapping was defined. | |
1574 | |
21771
fcf978444298
patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes
Bram Moolenaar <Bram@vim.org>
parents:
21717
diff
changeset
|
1575 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
|
1576 encountered, the script is not loaded until the `:def` function is called. |
27043
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1577 This also means you get any errors only at runtime, since the argument and |
15f40772e10a
patch 8.2.4050: Vim9: need to prefix every item in an autoload script
Bram Moolenaar <Bram@vim.org>
parents:
27036
diff
changeset
|
1578 return types are not known yet. |
21771
fcf978444298
patch 8.2.1435: Vim9: always converting to string for ".." leads to mistakes
Bram Moolenaar <Bram@vim.org>
parents:
21717
diff
changeset
|
1579 |
27162 | 1580 For testing the |test_override()| function can be used to have the |
1581 `import autoload` load the script right away, so that the items and types can | |
1582 be checked without waiting for them to be actually used: > | |
1583 test_override('autoload', 1) | |
1584 Reset it later with: > | |
1585 test_override('autoload', 0) | |
1586 Or: > | |
1587 test_override('ALL', 0) | |
1588 | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1589 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1590 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
|
1591 |
20856 | 1592 If an `import` statement is used in legacy Vim script, the script-local "s:" |
27162 | 1593 namespace will be used for the imported items, even when "s:" is not |
1594 specified. | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1595 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1596 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1597 ============================================================================== |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1598 |
22328 | 1599 6. Future work: classes *vim9-classes* |
1600 | |
1601 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
|
1602 Most of Vim9 script can be created without this functionality, and since |
22328 | 1603 implementing classes is going to be a lot of work, it is left for the future. |
1604 For now we'll just make sure classes can be added later. | |
1605 | |
1606 Thoughts: | |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1607 - `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
|
1608 - 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
|
1609 - A single constructor called "constructor" |
22328 | 1610 - 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
|
1611 - `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
|
1612 - `interface` / `endinterface` (abstract class without any implementation) |
22328 | 1613 - `class SomeClass implements SomeInterface` |
1614 - Generics for class: `class <Tkey, Tentry>` | |
1615 - Generics for function: `def <Tkey> GetLast(key: Tkey)` | |
1616 | |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1617 Again, much of this is from TypeScript with a slightly different syntax. |
22328 | 1618 |
1619 Some things that look like good additions: | |
1620 - Use a class as an interface (like Dart) | |
1621 - 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
|
1622 - Mixins |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1623 - For testing: Mock mechanism |
22328 | 1624 |
1625 An important class that will be provided is "Promise". Since Vim is single | |
1626 threaded, connecting asynchronous operations is a natural way of allowing | |
1627 plugins to do their work without blocking the user. It's a uniform way to | |
1628 invoke callbacks and handle timeouts and errors. | |
1629 | |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1630 Some examples: > |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1631 |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1632 abstract class Person |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1633 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
|
1634 var name: string |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1635 |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1636 def constructor(name: string) |
25402 | 1637 this.name = name |
24888
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1638 enddef |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1639 |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1640 def display(): void |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1641 echo name |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1642 enddef |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1643 |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1644 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
|
1645 endclass |
b6ac4ed5e2d2
patch 8.2.2982: Vim9: future commands are not reserved yet
Bram Moolenaar <Bram@vim.org>
parents:
24751
diff
changeset
|
1646 |
22328 | 1647 ============================================================================== |
1648 | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1649 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
|
1650 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1651 The :def command ~ |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1652 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1653 Plugin writers have asked for much faster Vim script. Investigations have |
19303 | 1654 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
|
1655 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
|
1656 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
|
1657 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
|
1658 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
|
1659 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
|
1660 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1661 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
|
1662 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
|
1663 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
|
1664 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
|
1665 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1666 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
|
1667 "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
|
1668 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1669 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1670 Type checking ~ |
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 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
|
1673 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
|
1674 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
|
1675 encountering the "+" character and compiling this into a generic add |
23666 | 1676 instruction, at runtime the instruction would have to inspect the type of the |
1677 arguments and decide what kind of addition to do. And when the type is | |
1678 dictionary throw an error. If the types are known to be numbers then an "add | |
1679 number" instruction can be used, which is faster. The error can be given at | |
1680 compile time, no error handling is needed at runtime, since adding two numbers | |
1681 cannot fail. | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1682 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1683 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
|
1684 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
|
1685 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
|
1686 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1687 |
22328 | 1688 Removing clutter and weirdness ~ |
20856 | 1689 |
22328 | 1690 Once decided that `:def` functions have different syntax than legacy functions, |
1691 we are free to add improvements to make the code more familiar for users who | |
1692 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
|
1693 only Vim does. |
22328 | 1694 |
1695 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
|
1696 backwards compatible with the good old Vi commands. |
20856 | 1697 |
22328 | 1698 Examples: |
1699 - Drop `:call` for calling a function and `:eval` for manipulating data. | |
1700 - Drop using a leading backslash for line continuation, automatically figure | |
1701 out where an expression ends. | |
20856 | 1702 |
22328 | 1703 However, this does require that some things need to change: |
1704 - 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
|
1705 This is good anyway, it is known from several popular languages. |
22328 | 1706 - Ex command ranges need to be prefixed with a colon, to avoid confusion with |
1707 expressions (single quote can be a string or a mark, "/" can be divide or a | |
1708 search command, etc.). | |
1709 | |
1710 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
|
1711 is accidentally used you are very likely to get an error message. |
20856 | 1712 |
1713 | |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1714 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
|
1715 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1716 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
|
1717 different from what they are used to. To reduce this complaint popular |
20856 | 1718 languages are used as an example. At the same time, we do not want to abandon |
1719 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
|
1720 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1721 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
|
1722 gaining popularity and has similarities with Vim script. It also has a |
22328 | 1723 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
|
1724 typing (a variable can have different types, this changes at runtime). Since |
22328 | 1725 legacy Vim script is dynamically typed and a lot of existing functionality |
1726 (esp. builtin functions) depends on that, while static typing allows for much | |
1727 faster execution, we need to have this mix in Vim9 script. | |
1728 | |
22171 | 1729 There is no intention to completely match TypeScript syntax and semantics. We |
1730 just want to take those parts that we can use for Vim and we expect Vim users | |
22328 | 1731 will be happy with. TypeScript is a complex language with its own history, |
1732 advantages and disadvantages. To get an idea of the disadvantages read the | |
1733 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
|
1734 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
|
1735 |
22328 | 1736 People familiar with other languages (Java, Python, etc.) will also find |
1737 things in TypeScript that they do not like or do not understand. We'll try to | |
1738 avoid those things. | |
22272
eb1f5f618c75
patch 8.2.1685: Vim9: cannot declare a constant value
Bram Moolenaar <Bram@vim.org>
parents:
22171
diff
changeset
|
1739 |
eb1f5f618c75
patch 8.2.1685: Vim9: cannot declare a constant value
Bram Moolenaar <Bram@vim.org>
parents:
22171
diff
changeset
|
1740 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
|
1741 - 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
|
1742 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
|
1743 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
|
1744 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
|
1745 - 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
|
1746 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
|
1747 annoying. Vim recognizes an expression with && or || and allows using the |
26755
ddaea8dcaff5
patch 8.2.3906: Vim9 help still contains "under development" warnings
Bram Moolenaar <Bram@vim.org>
parents:
26745
diff
changeset
|
1748 result as a bool. The |falsy-operator| was added for the mechanism to use a |
ddaea8dcaff5
patch 8.2.3906: Vim9 help still contains "under development" warnings
Bram Moolenaar <Bram@vim.org>
parents:
26745
diff
changeset
|
1749 default value. |
22272
eb1f5f618c75
patch 8.2.1685: Vim9: cannot declare a constant value
Bram Moolenaar <Bram@vim.org>
parents:
22171
diff
changeset
|
1750 - 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
|
1751 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
|
1752 Falsy. |
eb1f5f618c75
patch 8.2.1685: Vim9: cannot declare a constant value
Bram Moolenaar <Bram@vim.org>
parents:
22171
diff
changeset
|
1753 - 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
|
1754 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
|
1755 which is more flexible, but is only checked at runtime. |
27459 | 1756 - TypeScript has a complicated "import" statement that does not match how the |
1757 Vim import mechanism works. A much simpler mechanism is used instead, which | |
1758 matches that the imported script is only sourced once. | |
22171 | 1759 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1760 |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1761 Declarations ~ |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1762 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1763 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
|
1764 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
|
1765 `: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
|
1766 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
|
1767 |
23047 | 1768 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
|
1769 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
|
1770 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
|
1771 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
|
1772 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
|
1773 almost the same. |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1774 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1775 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
|
1776 :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
|
1777 :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
|
1778 :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
|
1779 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1780 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
|
1781 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
|
1782 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
|
1783 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
|
1784 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
|
1785 ... |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1786 name = 'John' |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1787 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
|
1788 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1789 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
|
1790 var mylist: list<string> |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1791 final mylist: list<string> = ['foo'] |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1792 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
|
1793 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1794 Two alternatives were considered: |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1795 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
|
1796 var list<string> mylist |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1797 final list<string> mylist = ['foo'] |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1798 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
|
1799 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
|
1800 var mylist list<string> |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1801 final mylist list<string> = ['foo'] |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1802 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
|
1803 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1804 The first is more familiar for anyone used to C or Java. The second one |
22565 | 1805 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
|
1806 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1807 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
|
1808 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
|
1809 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
|
1810 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
|
1811 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
|
1812 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1813 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
|
1814 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
|
1815 declaration. |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1816 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1817 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1818 Expressions ~ |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1819 |
22565 | 1820 Expression evaluation was already close to what other languages are doing. |
1821 Some details are unexpected and can be improved. For example a boolean | |
1822 condition would accept a string, convert it to a number and check if the | |
1823 number is non-zero. This is unexpected and often leads to mistakes, since | |
1824 text not starting with a number would be converted to zero, which is | |
22723 | 1825 considered false. Thus using a string for a condition would often not give an |
1826 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
|
1827 |
23047 | 1828 In Vim9 type checking is stricter to avoid mistakes. Where a condition is |
22565 | 1829 used, e.g. with the `:if` command and the `||` operator, only boolean-like |
1830 values are accepted: | |
1831 true: `true`, `v:true`, `1`, `0 < 9` | |
1832 false: `false`, `v:false`, `0`, `0 > 9` | |
1833 Note that the number zero is false and the number one is true. This is more | |
22723 | 1834 permissive than most other languages. It was done because many builtin |
22565 | 1835 functions return these values. |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1836 |
22565 | 1837 If you have any type of value and want to use it as a boolean, use the `!!` |
1838 operator: | |
24751 | 1839 true: `!!'text'`, `!![99]`, `!!{'x': 1}`, `!!99` |
22565 | 1840 false: `!!''`, `!![]`, `!!{}` |
1841 | |
1842 From a language like JavaScript we have this handy construct: > | |
1843 GetName() || 'unknown' | |
1844 However, this conflicts with only allowing a boolean for a condition. | |
1845 Therefore the "??" operator was added: > | |
1846 GetName() ?? 'unknown' | |
1847 Here you can explicitly express your intention to use the value as-is and not | |
1848 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
|
1849 |
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1850 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1851 Import and Export ~ |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1852 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1853 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
|
1854 are global. It is possible to make them script-local, but then they are not |
22171 | 1855 available in other scripts. This defies the concept of a package that only |
1856 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
|
1857 |
21825 | 1858 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
|
1859 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
|
1860 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
|
1861 - 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
|
1862 unless exported. |
22171 | 1863 - When importing a script the symbols that are imported are explicitly listed, |
1864 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
|
1865 - 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
|
1866 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
|
1867 - 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
|
1868 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
|
1869 - 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
|
1870 avoided. |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1871 - 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
|
1872 |
20856 | 1873 When sourcing a Vim9 script from a legacy script, only the items defined |
1874 globally can be used, not the exported items. Alternatives considered: | |
1875 - All the exported items become available as script-local items. This makes | |
22171 | 1876 it uncontrollable what items get defined and likely soon leads to trouble. |
20856 | 1877 - Use the exported items and make them global. Disadvantage is that it's then |
1878 not possible to avoid name clashes in the global namespace. | |
1879 - Completely disallow sourcing a Vim9 script, require using `:import`. That | |
1880 makes it difficult to use scripts for testing, or sourcing them from the | |
1881 command line to try them out. | |
22171 | 1882 Note that you can also use `:import` in legacy Vim script, see above. |
20856 | 1883 |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1884 |
22328 | 1885 Compiling functions early ~ |
1886 | |
1887 Functions are compiled when called or when `:defcompile` is used. Why not | |
1888 compile them early, so that syntax and type errors are reported early? | |
1889 | |
1890 The functions can't be compiled right away when encountered, because there may | |
1891 be forward references to functions defined later. Consider defining functions | |
1892 A, B and C, where A calls B, B calls C, and C calls A again. It's impossible | |
1893 to reorder the functions to avoid forward references. | |
1894 | |
1895 An alternative would be to first scan through the file to locate items and | |
1896 figure out their type, so that forward references are found, and only then | |
1897 execute the script and compile the functions. This means the script has to be | |
1898 parsed twice, which is slower, and some conditions at the script level, such | |
1899 as checking if a feature is supported, are hard to use. An attempt was made | |
1900 to see if it works, but it turned out to be impossible to make work nicely. | |
1901 | |
1902 It would be possible to compile all the functions at the end of the script. | |
1903 The drawback is that if a function never gets called, the overhead of | |
1904 compiling it counts anyway. Since startup speed is very important, in most | |
1905 cases it's better to do it later and accept that syntax and type errors are | |
1906 only reported then. In case these errors should be found early, e.g. when | |
1907 testing, the `:defcompile` command will help out. | |
1908 | |
1909 | |
22391
a9fb7efa31d6
patch 8.2.1744: Vim9: using ":const!" is weird
Bram Moolenaar <Bram@vim.org>
parents:
22328
diff
changeset
|
1910 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
|
1911 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1912 Vim supports interfaces to Perl, Python, Lua, Tcl and a few others. But |
22328 | 1913 these interfaces have never become widely used, for various reasons. When |
1914 Vim9 was designed a decision was made to make these interfaces lower priority | |
1915 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
|
1916 |
22328 | 1917 Still, plugin writers may find other languages more familiar, want to use |
1918 existing libraries or see a performance benefit. We encourage plugin authors | |
1919 to write code in any language and run it as an external tool, using jobs and | |
1920 channels. We can try to make this easier somehow. | |
1921 | |
1922 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
|
1923 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
|
1924 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
|
1925 tool need to be supported. Since most languages support classes the lack of |
22171 | 1926 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
|
1927 |
22328 | 1928 |
1929 Classes ~ | |
1930 | |
1931 Vim supports a kind-of object oriented programming by adding methods to a | |
1932 dictionary. With some care this can be made to work, but it does not look | |
1933 like real classes. On top of that, it's quite slow, because of the use of | |
1934 dictionaries. | |
19181
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1935 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1936 The support of classes in Vim9 script is a "minimal common functionality" of |
22171 | 1937 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
|
1938 popular programming language. |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1939 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1940 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1941 |
94eda51ba9ba
patch 8.2.0149: maintaining a Vim9 branch separately is more work
Bram Moolenaar <Bram@vim.org>
parents:
diff
changeset
|
1942 vim:tw=78:ts=8:noet:ft=help:norl: |