[Feature requset] Multiple inheritance in `@class` annotation or add new `@mixin` annotation

[alek13]

Lua is very flexible and allows you to do anything.

Sometimes we need something like multiple inheritance or rather mixins. When several functionality is mixed into the resulting class/table when “designing” the class programmatically.

Example

For example, something like: We have some base "mixer", that can mix different mixins to itself

-- /base_classes/Form/Base.lua

--- @class base_classes.Form.Mixin      @just interface for mixins
--- @field mix_to fun(base_class:base_classes.Form.Base)

--- @class base_classes.Form.Base
local BaseForm  = {
  -- ...
}

--- @param mixin base_classes.Form.Mixin
function BaseForm:mix(mixin)
    mixin.mix_to(self)
end

Then we have some Factory for “designing” the new class programmatically:

-- /base_classes/Form.lua
require('base_classes.Form.Base')

--- Form Class Factory class.
--- This class constructs for you a base form class.
---
--- @class base_classes.Form
--- @field for_node    fun(self:self):self  mixes `base_classes.Form.Mixin.ForNode` into your class
--- @field for_entity  fun(self:self):self  mixes `base_classes.Form.Mixin.ForEntity` into your class
--- @field ...
--- @field ...
local Form = {
    --- @param self  self
    --- @param mixin string
    __index = function(self, mixin)
        if not table.has_key(self.mixins) then
            return self[mixin]
        end

        return function()
            self.now_constructing = self.now_constructing or setmetatable({}, { __index = BaseForm })
            if not self.now_constructing then
                self.now_constructing:mix(ForNode)
            end
        end
    end
}

And we have several mixins for different purposes:

-- /base_classes/Form/Mixin/ForNode.lua

--- @class base_classes.Form.Mixin.ForNode: base_classes.Form.Mixin
--- @field for_node_any_var string
--- @field for_node_any_fun fun(self:base_classes.Form.Base)
--- @field for_node_...
--- @field for_node_...
local ForNode = {}

--- @static
--- @param base_class base_classes.Form.Base
function ForNode.mix_to(base_class)
    base_class.for_node_any_var = 'any_value'
    base_class.for_node_any_fun = function(self, some_var)
        -- ....
    end
    -- ...
end

-- /base_classes/Form/Mixin/ForEntity.lua

--- @class base_classes.Form.Mixin.ForEntity: base_classes.Form.Mixin
--- @field for_entity_...
--- @field for_entity_...
--- @field for_entity_...
local ForEntity = {}
-- ...

-- /base_classes/Form/Mixin/Personal.lua
-- ...

-- /base_classes/Form/Mixin/Shared.lua
-- ...

-- /base_classes/Form/Mixin/WithTabs.lua
-- ...

-- /base_classes/Form/Mixin/WithPlayerInventory.lua
-- ...

and so on....

---

So, then we can "construct"/design our own class like this:

-- /some_module/src/SomeForm.lua

local SomeForm = base_classes.Form:personal():for_node():with_tabs()

-- ...

---

Feature request

So.... It would be very useful, if we could specify from which mixins the class consists of. For example like this:

-- /some_module/src/SomeForm.lua

--- @class some_module.src.SomeForm: base_classes.Form.Base
--- @mixin base_classes.Form.Mixin.Personal
--- @mixin base_classes.Form.Mixin.ForNode
--- @mixin base_classes.Form.Mixin.WithTabs
local SomeForm = base_classes.Form :personal() :for_node() :with_tabs()

-- ...

or just like multiple inheritance:

-- /some_module/src/SomeForm.lua

--- @class some_module.src.SomeForm: base_classes.Form.Base, base_classes.Form.Mixin.Personal, base_classes.Form.Mixin.ForNode, base_classes.Form.Mixin.WithTabs
local SomeForm = base_classes.Form :personal() :for_node() :with_tabs()

-- ...

---

Related issues

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[CppCXY]

vscode emmylua supports multiple inheritance

[CppCXY]

You can also use vscodeemmylua's language server directly in intellij by installing LSP4IJ. VSCode-EmmyLua supports many advanced features and its performance far exceeds IntelliJ-EmmyLua. I will try to make IntelliJ-EmmyLua use the analysis backend of VSCode-EmmyLua.

[alek13]

@CppCXY , thanx for suggestion. Is there any chance, that it will be added to this plugin ?

[CppCXY]

maybe you can try my plugin: https://plugins.jetbrains.com/plugin/25076-emmylua2/edit/versions/stable/584455