Annotation Help: Mutated Classes

[NickGrease]

---@class MyClass
instance = MyClass.new()
instance.a = 4
instance.b = 5
instance:finalize()

---@class MyClassModified
instance...

After calling finalize, instance is modified in such a way to make all properties read-only, as well as having new() and finalize() removed. I'd like the editor to see instance as a 'new' class (both MyClass and MyClassModified are fully annotated elsewhere) after it has been finalized. Is it possible using the above semantics?, or do I need to make finalize() return the modified instance as a new class? I'm hoping to avoid:

mod_instance = instance:finalize()

Hope that makes sense, sorry if this is dumb.

[CppCXY]

I think use like this:

---@class MyClassData
---@field name string
---@field age number

---@class MyClassFactor : MyClassData
local factor = {}

---@return MyClassData
function factor.new()
    
end

[tomlau10]

I think what author wants is @cast, but seems it is not perfect

---@class MyClassModified
---@field a integer
---@field b integer

---@class MyClass: MyClassModified
local MyClass = {}

---@return MyClass
function MyClass.new() end

function MyClass:finalize() end

---

local instance = MyClass.new()
instance.a = 4
instance.b = 5
instance:finalize()

---@cast instance MyClassModified
-- dont know why this line throws `cast-type-mismatch`
-- how come casting a child class to parent class not allowed ?

instance:finalize() --> Undefined field `finalize`, good
-- but it will still auto suggest `finalize`, so not perfect

[NickGrease]

Thanks, tomlau10, I can live with the error. I can't remember if I tried cast, or just used it wrong, but this is close enough for me. Thanks again!

[tomlau10]

I can live with the error

Furthermore, you can use @diagnostic to disable the error for one line
https://luals.github.io/wiki/annotations/#diagnostic

---@diagnostic disable-next-line: cast-type-mismatch
---@cast instance MyClassModified

or even disable it globally in your setting or project's .luarc.json
https://luals.github.io/wiki/settings/#diagnosticsdisable

• .luarc.json

{
    "$schema": "https://raw.githubusercontent.com/sumneko/vscode-lua/master/setting/schema.json",
    "diagnostics.disable": [
        "cast-type-mismatch"
    ]
}

[NickGrease]

I ended up rewriting the class in such a way that the suggestions for each step work as I had hoped. Took a bit of effort but I can do the following and everything works. It's not exactly how I wanted it to work, but reworking the code simplified other aspects, so its a win for me.

    --EditableAudioContext
    local eac = AudioMaster.newAudioContext()
    --AudioContextSettings
    local acSettings = eac:newSettings()
    --AudioContext
    local ac = eac:finalizeSettings(acSettings)

[tomlau10]

or do I need to make finalize() return the modified instance as a new class? I'm hoping to avoid:

mod_instance = instance:finalize()

If what you want to avoid is creating another variable (thus avoid variable renaming in the rest of the code),
then you might just redefine the same named variable?

---@class MyClassModified
---@field a integer
---@field b integer

---@class MyClass: MyClassModified
local MyClass = {}

---@return MyClass
function MyClass.new()
    return {}
end

---@return MyClassModified
function MyClass:finalize()
    return self
end

---

local instance = MyClass.new()
instance.a = 4
instance.b = 5
local instance = instance:finalize()

instance.   -- now only suggests `a`, `b`, without `new` or `finalize`