Full Example

Here's a full example of using ReductionUtility as I do in my own projects.

--!optimize 2
-- I do not recommend strict mode, since it does not behave well.
local ReductionUtility = require("ReductionUtility")

local Reduction = {}

export type IncrementNumber = ReductionUtility.Action<"IncrementNumber"> & {Value: number}
Reduction.IncrementNumber = ReductionUtility.MakeActionCreator("IncrementNumber", function(value: number)
    return {
        Value = value,
    }
end)

export type SetNumber = ReductionUtility.Action<"SetNumber"> & {Value: number}
Reduction.SetNumber = ReductionUtility.MakeActionCreator("SetNumber", function(value: number)
    return {
        Value = value,
    }
end)

export type SetString = ReductionUtility.Action<"SetString"> & {Value: string}
Reduction.SetString = ReductionUtility.MakeActionCreator("SetString", function(value: string)
    return {
        Value = value,
    }
end)

export type UppercaseString = ReductionUtility.Action<"UppercaseString">
Reduction.UppercaseString = ReductionUtility.MakeActionCreator("UppercaseString", function()
    return {}
end)

export type IState = {
    Number: number,
    String: string,
}

local INITIAL_STATE: IState = table.freeze({
    Number = 0,
    String = "",
})
Reduction.InitialState = INITIAL_STATE

Reduction.Reducer = ReductionUtility.CreateReducer(INITIAL_STATE, {
    [Reduction.IncrementNumber.name] = function(state: IState, action: IncrementNumber)
        local new = table.clone(state)
        state.Number += action.Value
        return new
    end,

    [Reduction.SetNumber.name] = function(state: IState, action: SetNumber)
        local new = table.clone(state)
        state.Number = action.Value
        return new
    end,

    [Reduction.SetString.name] = function(state: IState, action: SetString)
        local new = table.clone(state)
        state.String = action.Value
        return new
    end,

    [Reduction.UppercaseString.name] = function(state: IState)
        local new = table.clone(state)
        state.String = string.upper(state.String)
        return new
    end,
})

table.freeze(Reduction)
return Reduction

Then you can pass the reducer to wherever you need it!