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patch 8.2.2982: Vim9: future commands are not reserved yet Commit: https://github.com/vim/vim/commit/742357718000927d652b1a98d313a3950571c8ec Author: Bram Moolenaar <Bram@vim.org> Date: Sat Jun 12 14:53:05 2021 +0200 patch 8.2.2982: Vim9: future commands are not reserved yet Problem: Vim9: future commands are not reserved yet. Solution: Add commands to be implemented later. Make "this" a reserved name.
author Bram Moolenaar <Bram@vim.org>
date Sat, 12 Jun 2021 15:00:03 +0200
parents e69e7133c9cf
children fd37be6dc258
comparison
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24887:670e100e6be6 24888:b6ac4ed5e2d2
1 *vim9.txt* For Vim version 8.2. Last change: 2021 May 26 1 *vim9.txt* For Vim version 8.2. Last change: 2021 Jun 12
2 2
3 3
4 VIM REFERENCE MANUAL by Bram Moolenaar 4 VIM REFERENCE MANUAL by Bram Moolenaar
5 5
6 6
167 `:def` has no options like `:function` does: "range", "abort", "dict" or 167 `:def` has no options like `:function` does: "range", "abort", "dict" or
168 "closure". A `:def` function always aborts on an error (unless `:silent!` was 168 "closure". A `:def` function always aborts on an error (unless `:silent!` was
169 used for the command or inside a `:try` block), does not get a range passed 169 used for the command or inside a `:try` block), does not get a range passed
170 cannot be a "dict" function, and can always be a closure. 170 cannot be a "dict" function, and can always be a closure.
171 171
172 Later classes will be added, which replaces the "dict function" mechanism.
173 For now you will need to pass the dictionary explicitly: >
174 def DictFunc(d: dict<any>, arg: string)
175 echo d[arg]
176 enddef
177 var d = {item: 'value', func: DictFunc}
178 d.func(d, 'item')
179
172 The argument types and return type need to be specified. The "any" type can 180 The argument types and return type need to be specified. The "any" type can
173 be used, type checking will then be done at runtime, like with legacy 181 be used, type checking will then be done at runtime, like with legacy
174 functions. 182 functions.
175 183
176 Arguments are accessed by name, without "a:", just like any other language. 184 Arguments are accessed by name, without "a:", just like any other language.
443 and for a lambda. Also, when a "{" is found the parser needs to figure out if 451 and for a lambda. Also, when a "{" is found the parser needs to figure out if
444 it is the start of a lambda or a dictionary, which is now more complicated 452 it is the start of a lambda or a dictionary, which is now more complicated
445 because of the use of argument types. 453 because of the use of argument types.
446 454
447 To avoid these problems Vim9 script uses a different syntax for a lambda, 455 To avoid these problems Vim9 script uses a different syntax for a lambda,
448 which is similar to Javascript: > 456 which is similar to JavaScript: >
449 var Lambda = (arg) => expression 457 var Lambda = (arg) => expression
450 458
451 No line break is allowed in the arguments of a lambda up to and including the 459 No line break is allowed in the arguments of a lambda up to and including the
452 "=>". This is OK: > 460 "=>". This is OK: >
453 filter(list, (k, v) => 461 filter(list, (k, v) =>
520 And when a dict spans multiple lines: > 528 And when a dict spans multiple lines: >
521 var mydict = { 529 var mydict = {
522 one: 1, 530 one: 1,
523 two: 2, 531 two: 2,
524 } 532 }
525 Function call: > 533 With a function call: >
526 var result = Func( 534 var result = Func(
527 arg1, 535 arg1,
528 arg2 536 arg2
529 ) 537 )
530 538
553 at the start of the line indicates line continuation: > 561 at the start of the line indicates line continuation: >
554 autocmd BufNewFile *.match if condition 562 autocmd BufNewFile *.match if condition
555 | echo 'match' 563 | echo 'match'
556 | endif 564 | endif
557 565
566 Note that this means that in heredoc the first line cannot be a bar: >
567 var lines =<< trim END
568 | this doesn't work
569 END
570 Either use an empty line at the start or do not use heredoc. Or temporarily
571 add the "C" flag to 'cpoptions': >
572 set cpo+=C
573 var lines =<< trim END
574 | this doesn't work
575 END
576 set cpo-=C
577 If the heredoc is inside a function 'cpoptions' must be set before :def and
578 restored after the :enddef.
579
580 In places where line continuation with a backslash is still needed, such as
581 splitting up a long Ex command, comments can start with #\ instead of "\: >
582 syn region Text
583 \ start='foo'
584 #\ comment
585 \ end='bar'
586
558 < *E1050* 587 < *E1050*
559 To make it possible for the operator at the start of the line to be 588 To make it possible for the operator at the start of the line to be
560 recognized, it is required to put a colon before a range. This will add 589 recognized, it is required to put a colon before a range. This example will
561 "start" and print: > 590 add "start" and print: >
562 var result = start 591 var result = start
563 + print 592 + print
564 Like this: > 593 Like this: >
565 var result = start + print 594 var result = start + print
566 595
608 2] [3, 637 2] [3,
609 4] 638 4]
610 < This does not work: > 639 < This does not work: >
611 echo [1, 2] 640 echo [1, 2]
612 [3, 4] 641 [3, 4]
642 - In some cases it is difficult for Vim to parse a command, especially when
643 commands are used as an argument to another command, such as `windo`. In
644 those cases the line continuation with a backslash has to be used.
613 645
614 646
615 White space ~ 647 White space ~
616 648
617 Vim9 script enforces proper use of white space. This is no longer allowed: > 649 Vim9 script enforces proper use of white space. This is no longer allowed: >
1238 export var someValue = ... 1270 export var someValue = ...
1239 export final someValue = ... 1271 export final someValue = ...
1240 export const someValue = ... 1272 export const someValue = ...
1241 export def MyFunc() ... 1273 export def MyFunc() ...
1242 export class MyClass ... 1274 export class MyClass ...
1275 export interface MyClass ...
1243 1276
1244 As this suggests, only constants, variables, `:def` functions and classes can 1277 As this suggests, only constants, variables, `:def` functions and classes can
1245 be exported. {not implemented yet: export class} 1278 be exported. {not implemented yet: class, interface}
1246 1279
1247 *E1042* 1280 *E1042*
1248 `:export` can only be used in Vim9 script, at the script level. 1281 `:export` can only be used in Vim9 script, at the script level.
1249 1282
1250 1283
1340 Most of Vim9 script can be created without this functionality, and since 1373 Most of Vim9 script can be created without this functionality, and since
1341 implementing classes is going to be a lot of work, it is left for the future. 1374 implementing classes is going to be a lot of work, it is left for the future.
1342 For now we'll just make sure classes can be added later. 1375 For now we'll just make sure classes can be added later.
1343 1376
1344 Thoughts: 1377 Thoughts:
1345 - `class` / `endclass`, everything in one file 1378 - `class` / `endclass`, the whole class must be in one file
1346 - Class names are always CamelCase 1379 - Class names are always CamelCase (to avoid a name clash with builtin types)
1347 - Single constructor 1380 - A single constructor called "constructor"
1348 - Single inheritance with `class ThisClass extends BaseClass` 1381 - Single inheritance with `class ThisClass extends BaseClass`
1349 - `abstract class` 1382 - `abstract class` (class with incomplete implementation)
1350 - `interface` (Abstract class without any implementation) 1383 - `interface` / `endinterface` (abstract class without any implementation)
1351 - `class SomeClass implements SomeInterface` 1384 - `class SomeClass implements SomeInterface`
1352 - Generics for class: `class <Tkey, Tentry>` 1385 - Generics for class: `class <Tkey, Tentry>`
1353 - Generics for function: `def <Tkey> GetLast(key: Tkey)` 1386 - Generics for function: `def <Tkey> GetLast(key: Tkey)`
1354 1387
1355 Again, much of this is from TypeScript. 1388 Again, much of this is from TypeScript with a slightly different syntax.
1356 1389
1357 Some things that look like good additions: 1390 Some things that look like good additions:
1358 - Use a class as an interface (like Dart) 1391 - Use a class as an interface (like Dart)
1359 - Extend a class with methods, using an import (like Dart) 1392 - Extend a class with methods, using an import (like Dart)
1393 - Mixins
1394 - For testing: Mock mechanism
1360 1395
1361 An important class that will be provided is "Promise". Since Vim is single 1396 An important class that will be provided is "Promise". Since Vim is single
1362 threaded, connecting asynchronous operations is a natural way of allowing 1397 threaded, connecting asynchronous operations is a natural way of allowing
1363 plugins to do their work without blocking the user. It's a uniform way to 1398 plugins to do their work without blocking the user. It's a uniform way to
1364 invoke callbacks and handle timeouts and errors. 1399 invoke callbacks and handle timeouts and errors.
1400
1401 Some examples: >
1402
1403 abstract class Person
1404 static const prefix = 'xxx'
1405 var name: string
1406
1407 def constructor(name: string)
1408 this.name = name;
1409 enddef
1410
1411 def display(): void
1412 echo name
1413 enddef
1414
1415 abstract def find(string): Person
1416 endclass
1365 1417
1366 ============================================================================== 1418 ==============================================================================
1367 1419
1368 9. Rationale *vim9-rationale* 1420 9. Rationale *vim9-rationale*
1369 1421