Pass declared record key as parameter

[PedroHase]

Hey all, I want to declare a function from a global extension where a parameter should hold the value of a record.

E.g. suppose I have following function that I want to declare:

MP.CreateEventTimer(event_name: string, interval_ms: number, [strategy: CallStrategy])

CallStrategy encodes a number value and is exposed by the extension through

MP.CallStrategy.BestEffort
MP.CallStrategy.Precise

How would I be able to declare CreateEventTimer so that I would be able to call?

MP.CreateEventTimer("testEvent", 1000, MP.CallStrategy.BestEffort)

My declaration attempt: Teal-Playground

-- declare MP
global record MP
    record CallStrategy
        BestEffort: any
        Precise: any
    end
    CreateEventTimer: function(eventName: string, timerInMS: number, strategy: MP.CallStrategy): nil
end

-- test CreateEventTimer
MP.CreateEventTimer("testEvent", 1000, MP.CallStrategy.Precise)
-- Error: argument 3: got <any type>, expected MP.CallStrategy

[hishamhm]

@PedroHase You can do something like this:

-- declare MP
global record MP
    record CallStrategyType
        -- what do call strategies have in common?
    end
    record CallStrategy
        BestEffort: CallStrategyType
        Precise: CallStrategyType
    end
    CreateEventTimer: function(eventName: string, timerInMS: number, strategy: MP.CallStrategyType): nil
end

-- test CreateEventTimer
MP.CreateEventTimer("testEvent", 1000, MP.CallStrategy.Precise)

[hishamhm]

With the code in the latest master (which fixes typechecking of enum keys in maps when using dot-notation), you could alternatively declare CallStrategy as a map like this:

-- declare MP
global record MP
    record CallStrategyType
        -- what do call strategies have in common?
    end
    enum CallStrategyName
        "BestEffort"
        "Precise"
    end
    CallStrategy: {CallStrategyName:CallStrategyType}
    CreateEventTimer: function(eventName: string, timerInMS: number, strategy: MP.CallStrategyType): nil
end

-- test CreateEventTimer
MP.CreateEventTimer("testEvent", 1000, MP.CallStrategy.Precise)

[PedroHase]

Thanks for your help @hishamhm, highly appreciated 😊 ! Is there an ETA for when the next release will drop that contains the fix (i.e. if it would be better to wait, or use your first solution)?

[hishamhm]

I think the first solution works just as well.

I want to get some feedback for a few days to see if there are any uncaught regressions in the code I pushed recently, so I'll give at least a couple of weeks until the next release. You can try the latest code now with luarocks install tl --dev if you're running it from LuaRocks (luarocks install tl will install the stable release back).