diff options
Diffstat (limited to 'runtime/doc/vim9class.txt')
| -rw-r--r-- | runtime/doc/vim9class.txt | 153 |
1 files changed, 138 insertions, 15 deletions
diff --git a/runtime/doc/vim9class.txt b/runtime/doc/vim9class.txt index a00a5b7..ef96aa9 100644 --- a/runtime/doc/vim9class.txt +++ b/runtime/doc/vim9class.txt @@ -1,4 +1,4 @@ -*vim9class.txt* For Vim version 9.1. Last change: 2024 Mar 03 +*vim9class.txt* For Vim version 9.1. Last change: 2024 Apr 13 VIM REFERENCE MANUAL by Bram Moolenaar @@ -328,10 +328,27 @@ variables but they have no access to the object variables, they cannot use the enddef endclass -Inside the class the class method can be called by name directly, outside the -class the class name must be prefixed: `OtherThing.ClearTotalSize()`. To use -a class method from a parent class in a child class, the class name must be -prefixed. +Inside the class, the class method can be called by name directly, outside the +class, the class name must be prefixed: `OtherThing.ClearTotalSize()`. Also, +the name prefix must be used for public class methods in the special contexts +of class variable initializers and of lambda expressions and nested functions: +> + class OtherThing + static var name: string = OtherThing.GiveName() + + static def GiveName(): string + def DoGiveName(): string + return OtherThing.NameAny() + enddef + + return DoGiveName() + enddef + + static def NameAny(): string + return "any" + enddef + endclass +< Just like object methods the access can be made protected by using an underscore as the first character in the method name: > @@ -576,7 +593,7 @@ A class is defined between `:class` and `:endclass`. The whole class is defined in one script file. It is not possible to add to a class later. A class can only be defined in a |Vim9| script file. *E1316* -A class cannot be defined inside a function. +A class cannot be defined inside a function. *E1429* It is possible to define more than one class in a script file. Although it usually is better to export only one main class. It can be useful to define @@ -904,19 +921,125 @@ aliased: > 8. Enum *Vim9-enum* *:enum* *:endenum* -{not implemented yet} - + *enum* *E1418* *E1419* *E1420* An enum is a type that can have one of a list of values. Example: > - :enum Color - White - Red - Green - Blue - Black - :endenum + :enum Color + White, + Red, + Green, Blue, Black + :endenum +< + *enumvalue* *E1422* +The enum values are separated by commas. More than one enum value can be +listed in a single line. The final enum value should not be followed by a +comma. + +An enum value is accessed using the enum name followed by the value name: > + + var a: Color = Color.Blue +< +Enums are treated as classes, where each enum value is essentially an instance +of that class. Unlike typical object instantiation with the |new()| method, +enum instances cannot be created this way. + +An enum can only be defined in a |Vim9| script file. *E1414* +An enum cannot be defined inside a function. + + *E1415* +An enum name must start with an uppercase letter. The name of an enum value +in an enum can start with an upper or lowercase letter. + + *E1416* +An enum can implement an interface but cannot extend a class: > + enum MyEnum implements MyIntf + Value1, + Value2 + def SomeMethod() + enddef + endenum +< + *enum-constructor* +The enum value objects in an enum are constructed like any other objects using +the |new()| method. Arguments can be passed to the enum constructor by +specifying them after the enum value name, just like calling a function. The +default constructor doesn't have any arguments. + + *E1417* +An enum can contain class variables, class methods, object variables and +object methods. The methods in an enum cannot be |:abstract| methods. + +The following example shows an enum with object variables and methods: > + + vim9script + enum Planet + Earth(1, false), + Jupiter(95, true), + Saturn(146, true) + + var moons: number + var has_rings: bool + def GetMoons(): number + return this.moons + enddef + endenum + echo Planet.Jupiter.GetMoons() + echo Planet.Earth.has_rings +< + *E1421* *E1423* *E1424* *E1425* +Enums and their values are immutable. They cannot be utilized as numerical or +string types. Enum values can declare mutable instance variables. + + *enum-name* +Each enum value object has a "name" instance variable which contains the name +of the enum value. This is a readonly variable. + + *enum-ordinal* *E1426* +Each enum value has an associated ordinal number starting with 0. The ordinal +number of an enum value can be accessed using the "ordinal" instance variable. +This is a readonly variable. Note that if the ordering of the enum values in +an enum is changed, then their ordinal values will also change. + + *enum-values* +All the values in an enum can be accessed using the "values" class variable +which is a List of the enum objects. This is a readonly variable. + +Example: > + enum Planet + Mercury, + Venus, + Earth + endenum + + echo Planet.Mercury + echo Planet.Venus.name + echo Planet.Venus.ordinal + for p in Planet.values + # ... + endfor +< +An enum is a class with class variables for the enum value objects and object +variables for the enum value name and the enum value ordinal: > + + enum Planet + Mercury, + Venus + endenum +< +The above enum definition is equivalent to the following class definition: > + + class Planet + public static final Mercury: Planet = Planet.new('Mercury', 0) + public static final Venus: Planet = Planet.new('Venus', 1) + + public static const values: list<Planet> = [Planet.Mercury, Planet.Venus] + + public const name: string + public const ordinal: number + endclass +< ============================================================================== 9. Rationale |