Re: case mappings

[Matthew Flatt <mflatt@xxxxxxxxxxx>]

At Wed, 13 Jul 2005 12:57:53 +0900, Alex Shinn wrote:
> This isn't just a "locale-awareness" problem.  True, the mappings in
> UnicodeData.txt are for simplicity only the 1-1 mappings, but
> SpecialCasing.txt includes a large number of mappings that aren't 1-1
> regardless of locale.  The Unicode concept of locale-independent
> case-mapping includes these special cases.  Without handling these
> cases, R6RS would be using an incomplete case mapping rule,
> which is therefore not usable in the general sense.

I appreciate this line of reasoning, and I'm now convinced that SRFI-75
(and R6RS) should include locale-independent procedures

  string-upcase
  string-downcase
  string-titlecase

that use the locale-independent part of SpecialCasing.txt. I'll add
that to the SRFI, pending further discussion.

Although I agree that the 1-1 mapping is of limited use, my impression
and experience is that it's still useful (if, for nothing else,
interfacing to older code that uses a 1-1 mapping). So, pending further
discussion, I will leave the character-casing operations in place.

As for locales, after some discussion among the editors, we decided
that this SRFI will not contain any locale-specific operations. Other
SRFIs/libraries will have to tackle that problem.

Matthew