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.
diff --git a/runtime/doc/vim9.txt b/runtime/doc/vim9.txt
index 6c25882..406aedc 100644
--- a/runtime/doc/vim9.txt
+++ b/runtime/doc/vim9.txt
@@ -1,4 +1,4 @@
-*vim9.txt* For Vim version 8.2. Last change: 2021 May 26
+*vim9.txt* For Vim version 8.2. Last change: 2021 Jun 12
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -169,6 +169,14 @@
used for the command or inside a `:try` block), does not get a range passed
cannot be a "dict" function, and can always be a closure.
+Later classes will be added, which replaces the "dict function" mechanism.
+For now you will need to pass the dictionary explicitly: >
+ def DictFunc(d: dict<any>, arg: string)
+ echo d[arg]
+ enddef
+ var d = {item: 'value', func: DictFunc}
+ d.func(d, 'item')
+
The argument types and return type need to be specified. The "any" type can
be used, type checking will then be done at runtime, like with legacy
functions.
@@ -445,7 +453,7 @@
because of the use of argument types.
To avoid these problems Vim9 script uses a different syntax for a lambda,
-which is similar to Javascript: >
+which is similar to JavaScript: >
var Lambda = (arg) => expression
No line break is allowed in the arguments of a lambda up to and including the
@@ -522,7 +530,7 @@
one: 1,
two: 2,
}
-Function call: >
+With a function call: >
var result = Func(
arg1,
arg2
@@ -555,10 +563,31 @@
| echo 'match'
| endif
+Note that this means that in heredoc the first line cannot be a bar: >
+ var lines =<< trim END
+ | this doesn't work
+ END
+Either use an empty line at the start or do not use heredoc. Or temporarily
+add the "C" flag to 'cpoptions': >
+ set cpo+=C
+ var lines =<< trim END
+ | this doesn't work
+ END
+ set cpo-=C
+If the heredoc is inside a function 'cpoptions' must be set before :def and
+restored after the :enddef.
+
+In places where line continuation with a backslash is still needed, such as
+splitting up a long Ex command, comments can start with #\ instead of "\: >
+ syn region Text
+ \ start='foo'
+ #\ comment
+ \ end='bar'
+
< *E1050*
To make it possible for the operator at the start of the line to be
-recognized, it is required to put a colon before a range. This will add
-"start" and print: >
+recognized, it is required to put a colon before a range. This example will
+add "start" and print: >
var result = start
+ print
Like this: >
@@ -610,6 +639,9 @@
< This does not work: >
echo [1, 2]
[3, 4]
+- In some cases it is difficult for Vim to parse a command, especially when
+ commands are used as an argument to another command, such as `windo`. In
+ those cases the line continuation with a backslash has to be used.
White space ~
@@ -1240,9 +1272,10 @@
export const someValue = ...
export def MyFunc() ...
export class MyClass ...
+ export interface MyClass ...
As this suggests, only constants, variables, `:def` functions and classes can
-be exported. {not implemented yet: export class}
+be exported. {not implemented yet: class, interface}
*E1042*
`:export` can only be used in Vim9 script, at the script level.
@@ -1342,27 +1375,46 @@
For now we'll just make sure classes can be added later.
Thoughts:
-- `class` / `endclass`, everything in one file
-- Class names are always CamelCase
-- Single constructor
+- `class` / `endclass`, the whole class must be in one file
+- Class names are always CamelCase (to avoid a name clash with builtin types)
+- A single constructor called "constructor"
- Single inheritance with `class ThisClass extends BaseClass`
-- `abstract class`
-- `interface` (Abstract class without any implementation)
+- `abstract class` (class with incomplete implementation)
+- `interface` / `endinterface` (abstract class without any implementation)
- `class SomeClass implements SomeInterface`
- Generics for class: `class <Tkey, Tentry>`
- Generics for function: `def <Tkey> GetLast(key: Tkey)`
-Again, much of this is from TypeScript.
+Again, much of this is from TypeScript with a slightly different syntax.
Some things that look like good additions:
- Use a class as an interface (like Dart)
- Extend a class with methods, using an import (like Dart)
+- Mixins
+- For testing: Mock mechanism
An important class that will be provided is "Promise". Since Vim is single
threaded, connecting asynchronous operations is a natural way of allowing
plugins to do their work without blocking the user. It's a uniform way to
invoke callbacks and handle timeouts and errors.
+Some examples: >
+
+ abstract class Person
+ static const prefix = 'xxx'
+ var name: string
+
+ def constructor(name: string)
+ this.name = name;
+ enddef
+
+ def display(): void
+ echo name
+ enddef
+
+ abstract def find(string): Person
+ endclass
+
==============================================================================
9. Rationale *vim9-rationale*