UuidGenerationTools

local hex = "1234567890abcdef"
local R = "ab89"

function next()
    str = ""
    for i = 1, 8 do
        rnd = math.random(#hex)
        str = str .. string.sub(hex, rnd, rnd)
    end
    str = str .. "-"
    for i = 1, 4 do
        rnd = math.random(#hex)
        str = str .. string.sub(hex, rnd, rnd)
    end
    str = str .. "-4"
    for i = 1, 3 do
        rnd = math.random(#hex)
        str = str .. string.sub(hex, rnd, rnd)
    end
    rnd = math.random(#R)
    str = str .. "-" .. string.sub(R, rnd, rnd)
    for i = 1, 3 do
        rnd = math.random(#hex)
        str = str .. string.sub(hex, rnd, rnd)
    end
    str = str .. "-"
    for i = 1, 12 do
        rnd = math.random(#hex)
        str = str .. string.sub(hex, rnd, rnd)
    end
    return str
end

return {next = next}