[I18n-sig] case insensitivity for Python 3K

[Tim Peters]

[Henry S. Thompson]
> ... if there's any thought of moving beyond ASCII for
> identifiers in Python 3K, then case insensitivity is
> potentially _very_ confusing and confounding move:  case
> folding is just not well-formed in lots of linguages,
> including real obscure ones such as French :-).

[Guido]
> True, but Unicode defines rigorously how case mappings should be
> done, and the Python Unicode support implements these as toupper()
> and tolower().  We could just say "whatever these do is the language
> definition".
>
> So I don't see this as an extra argument against case folding (on
> top of the excellent arguments that have already been given).

Except that Unicode's well-definedness is not the same as Henry's
well-formedness:  the mappings may well surprise the heck out of native
writers, and don't forget about Unicode titlecase either (which appears more
relevant than Unicode uppercase for VariablesWrittenInThisStyle).

Kinda like floating point is rigorously defined by IEEE-754, but that
doesn't mean it's not agonizingly surprising.  You don't have a lot of
choice about supporting fp in some way, but deciding to conflate case is
purely self-inflicted <wink>.

the-more-i-learn-of-the-world-the-more-i-cling-to-ascii-ly y'rs
    - tim