// Rot-13 encoding/decoding. rot13[str] := { chars = chars[str] ret = new array for c = chars { if (c >= char["A"] and c <= char["Z"]) c = ((c - char["A"] + 13) mod 26) + char["A"] else if (c >= char["a"] and c <= char["z"]) c = ((c - char["a"] + 13) mod 26) + char["a"] ret.push[c]; } return char[ret]; }