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Re: [Scheme-reports] Character/string case and the unicode module

On Sun, May 08, 2011 at 01:18:29AM -0400, John Cowan wrote:
> Jeronimo Pellegrini scripsit:
> > According to section 6.3.5 string-upcase, string-downcase and
> > string-ci* procedures are in the (scheme unicode) module.
> >
> > But since section 1.3.1 mandates that modules are implemented in
> > theor totality or not at all, then this means that an ASCII-only
> > implementation cannot offer those procedures except if it provides the
> > full Unicode module.
> Implementing the (scheme unicode) module does not imply that you support
> all of Unicode, or even any of it beyond ASCII.  It's simply that
> routines in that module require certain mapping tables which are proper
> or improper subsets of the Unicode mapping tables.  Consequently, if you
> do not need these procedures, you do not need those tables.

Yes, I meant I would need to bind string-ni=? for example,
even though it makes no sense to an ASCII-only system.

> > If this is correct, then the programmer would have to write something
> > like
> >
> > (import (scheme unicode))
> >
> > in order to use string-upcase (and char-upcase and lots of other
> > procedures perfectly meaningful for), even though that implementation
> > has no Unicode support.
> Correct.  That ensures portability between implementations.

Ah, OK -- that makes sense now!


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