CC: BOM test

function Utf8to32(utf8str)
    assert(type(utf8str) == "string")
    local res, seq, val = {}, 0, nil
    for i = 1, #utf8str do
        local c = string.byte(utf8str, i)
        if seq == 0 then
            table.insert(res, val)
            seq = c < 0x80 and 1 or c < 0xE0 and 2 or c < 0xF0 and 3 or
                  c < 0xF8 and 4 or c < 0xFC and 5 or c < 0xFE and 6 or
                  error("invalid UTF-8 character sequence")
            val = bit.band(c, 2^(8-seq) - 1)
        else
            val = bit.bor(bit.lshift(val, 6), bit.band(c, 0x3F))
        end
        seq = seq - 1
    end
    table.insert(res, val)
    table.insert(res, 0)
    return res
end

print(textutils.serialize(Utf8to32(...)))