memoize function example

memoize_fn.lua

-- example of Memoize function with color generation. Saves speed!
-- saves colors being used, and appends with new colors.
local results = {}
setmetatable(results, {__mode = "v"})

function create_RGB(r,g,b)
    -- defining key by the colors used
    local key = string.format("%d-%d-%d", r,g,b)
    local color = results[key]

    if color == nil then
        color = {red = r, green = g, blue = b}
        results[key] = color
    end

    return color
end