Switch Module

--[[Switch-Case Simulation in Lua

DOCUMENTATION

SWITCH MODULE

    local Switch = require(script.Switch) --returns a callable function for constructing Switch objects

Switch Object

    __call(variable) - Checks a specified variable amongst case statements. Uses :default if no value is found. If :default is not declared, this will error

    self :case(value, callback) - Sets a case value to callback, returns the object so that it can be chained
    self :default(callback) - Sets the default callback


EXAMPLE

local Switch = require(script.Switch)

local SpeedCase = Switch()
    :case(16, function()
        print("Hello Sixteen")
    end)

    :case(30, function()
        print("Hello Thirty")
    end)

    :default(function()
        print("Unrecognised")
    end)

SpeedCase(script.Parent.Humanoid.WalkSpeed)

]]--

local switchObjectMethods = {}
switchObjectMethods.__index = switchObjectMethods

switchObjectMethods.__call = function(self, variable)
    local c = self._callbacks[variable] or self._default
    if not c then
        error("No case statement defined for variable, and :default is not defined")
    end

    c()
end

function switchObjectMethods:case(v, f)
    self._callbacks[v] = f
    return self
end

function switchObjectMethods:default(f)
    self._default = f
    return self
end

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return function()
    local o = setmetatable({}, switchObjectMethods)
    o._callbacks = {}
    return o
end