[PATCH] Move charsets-in-region to C

[Stephen J. Turnbull]

Moving to xemacs-beta.

Aidan Kehoe writes:

 >  > Do you think [introducing a `map-text' API is] overkill?
 > 
 > Hmm, a little. Tangentally I was considering implementing
 > with-string-as-buffer-text in C for the sake of charsets-in-string and
 > decode-coding-string , but almost nothing else appears to use them, so it
 > may not be worth the maintenance. 

The kind of thing I'm thinking about is stuff like Didier Verna's
proposal to have a scannerless parser (ie, characters are tokens,
everything else is built up from context-free grammar).  (I'm not sure
he made that proposal publically, it was sort of a comment on my synfl
package.)

Didier wanted to write it in C, I'd like to be able to prototype stuff
like that in Lisp, though, even if ultimately we implement in C.