Re: Rewrite of Data.Char library?

Colin Paul Adams wrote:

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"Ahn" == Ahn, Ki Yung writes:

Ahn> Just a follow-up to add, and my suggestions. Lowercase and Ahn> Uppercase problem seems not to be solvable, since in some Ahn> languages like German sz doesn't have a good definition for Ahn> an uppercase letter.

You just follow the Unicode default foldings.

Note that these foldings are not inverses of each other - intuition is misplaced here.

Agreed. The real problem I think, as I've mentioned in the second posting is that isAlpha is neither backward compatible nor conforms to the Haskell 98 report. I suggest that we revert isAlpha back to the definition of Haskell 98 report and just add a new function called isLetter for what current implementation of Data.Char.isAlpha is doing. If this is controversial, I think there wouldn't be any problem that at least isAlpha in Char, the good old Haskell 98 standard libary module, should conform to the Haskell 98 definition, which is either isUpper or isLower.