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Maps

Maps (a.k.a. Dictionaries) are quite simple.

A map represents a set of keys and values in a table.(1)

  1. I.e., This is something you might want to represent with a map:

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    local abc = { [tostring(math.random())] = 255 }

You can define a valid map Datatype using a simple table, just like luau:

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local ty = light.datatypes

local some_map = { [ty.str()] = ty.u8 }

Using the above table syntax will behave the same as passing the table into the API shown below.

function light.datatypes.map

Shared Synchronous
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function map<Key, Value>(
    key: Datatype<Key>,
    value: Datatype<Value>,
    length: Datatype<number>?
): (Datatype<{ [Key]: Value }>)

First two arguments should be any Datatypes which cannot be nil. The length parameter should represent the number of keys in the map, and will default to datatypes.u16.

The length datatype should NOT be a regular number—instead: use a datatype that represents a number, like a uint, or a range.

A couple of ways you could use the optional length parameter:

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local some_map = ty.map( ty.str(), ty.u8, ty.u8 ) -- between 0-255 keys.

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local some_map = ty.map( ty.str(), ty.u8, ty.range(0, 50) ) -- Map should have between 0 and 50 keys.

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local some_map = ty.map( ty.str(), ty.u8, ty.literal(3) ) -- Map will always have three keys.