Lua Switch Statement

-- NOTE: This function does not currently work with tables however I plan on adding that in the near future.

local function switch(val, ...)
    local allowedTypes = {
        "number",
        "string"
    }
    local allow = false
    for _, t in pairs(allowedTypes) do
        if typeof(val) == t then
            allow = true
            break
        end
    end
    if not allow then
        error("Invalid switch variable type")
    end
    ---
    local cases = {...}
    local default
    if type(cases[#cases]) == 'function' then
        default = cases[#cases]
        table.remove(cases, #cases)
    end

    local caseVals = {}
    for _, case in pairs(cases) do
        table.insert(caseVals, case[1])
    end
    for i1, v1 in pairs(caseVals) do
        for i2, v2 in pairs(caseVals) do
            if v1 == v2 and i1 ~= i2 then
                error("Duplicate case error: case #"..i2.." is a duplicate of case #"..i1)
            end
        end
    end

    for _, case in pairs(cases) do
        if val == case[1] then
            return case[2]()
        end
    end
    if default then
        return default()
    end
end

-- USAGE EXAMPLE:
local nutrition
local food = "Pizza"
switch(food,
{"Fruit",
    function()
        nutrition = 100
    end
},
{"Beef",
    function()
        nutrition = 75
    end
},
{"Pizza",
    function()
        nutrition = 40
    end
},
{"Candy",
    function()
        nutrition = 10
    end
},
{"Salad",
    function()
        nutrition = 95
    end
},
function()
    nutrition = 50
end)
print(food.." has a nutritional value of "..nutrition)

--[[    Processing/Java code translation
int nutrition;
String food = "Pizza";

switch(food) {
    case "Fruit":
        nutrition = 100;
        break;

    case "Beef":
        nutrition = 75;
        break;

    case "Pizza":
        nutrition = 40;
        break;

    case "Candy":
        nutrition = 10;
        break;

    case "Salad":
        nutrition = 95;
        break;

    default:
        nutrition = 50;
        break;
}
println(food + " has a nutritional value of " + nutrition);
--]]