String complements

Dimitre Novatchev <dnovatchev@gmail.com> writes:
>    This function can easily handle strings - produce a "string complement" in the value space for a particular collation.
>        
>    For a simplified example, revert("abc") would produce "zyx" . This is doable and really valuable.

In what sense is “zyx” the complement of “abc”? Over what set of codepoints and in what collation?

I am very skeptical that such a function is well defined across all collations and will always produce a single, correct result in all cases.

Can you provide a detailed description of how this would work?

                                        Be seeing you,
                                          norm

--
Norm Tovey-Walsh
Saxonica