Mon, 23 Jul 2001 11:23:30 -0700, Mark P Jones <mpj@cse.ogi.edu> pisze:

I guess the intention here is that:

symbol -> ascSymbol | uniSymbol_<special | _ | : | " | '>

Right.

In fact, since all the characters in ascSymbol are either punctuation or symbols in Unicode, the inclusion of ascSymbol is redundant, and a better specification might be:

symbol -> uniSymbol_<special | _ | : | " | '>

It would still be nice to explicitly list ASCII symbols, so one doesn't need to look at Unicode specs to use ASCII-only source. There are two places when character predicates are used in Haskell: program source and module Char. I'm sure that we all agree that they should be consistent with each other. Some predicates in module Char are "wrong", i.e. I don't agree with their meaning. For example that isSpace is restricted to ISO-8859-1, and that caseless letters are considered uppercase. It's not clear what good definitions are, or even what set of predicates is useful, because there is no single official source with unambiguous and complete set of predicates. There are Unicode character categories, Unicode property lists, and implementations of C character predicates - all with different data. I guess Java specs have something to tell here too. I have an implemented proposal of improved Char predicates in QForeign <http://sf.net/projects/qforeign/>. Definitions are based on both Unicode character categories and PropList.txt from Unicode. -- __("< Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.ids.net.pl/ \__/ ^^ SYGNATURA ZASTÊPCZA QRCZAK