new modules for locale dependent Unicode string comparisons

[Bruno Haible]

I've added a set of Unicode string comparison functions which use the collation
rules of the current locale.


2009-03-07  Bruno Haible  <address@hidden>

        New module 'uninorm/u32-normcoll'.
        * lib/uninorm/u32-normcoll.c: New file.
        * modules/uninorm/u32-normcoll: New file.

        New module 'uninorm/u16-normcoll'.
        * lib/uninorm/u16-normcoll.c: New file.
        * modules/uninorm/u16-normcoll: New file.

        New module 'uninorm/u8-normcoll'.
        * lib/uninorm.h (u8_normcoll, u16_normcoll, u32_normcoll): New
        declarations.
        * lib/uninorm/u8-normcoll.c: New file.
        * lib/uninorm/u-normcoll.h: New file.
        * modules/uninorm/u8-normcoll: New file.

        New module 'uninorm/u32-normxfrm'.
        * lib/uninorm/u32-normxfrm.c: New file.
        * modules/uninorm/u32-normxfrm: New file.

        New module 'uninorm/u16-normxfrm'.
        * lib/uninorm/u16-normxfrm.c: New file.
        * modules/uninorm/u16-normxfrm: New file.

        New module 'uninorm/u8-normxfrm'.
        * lib/uninorm.h (u8_normxfrm, u16_normxfrm, u32_normxfrm): New
        declarations.
        * lib/uninorm/u8-normxfrm.c: New file.
        * lib/uninorm/u-normxfrm.h: New file.
        * modules/uninorm/u8-normxfrm: New file.

========================= new decls in lib/uninorm.h 
=================================

/* Converts the string S of length N to a string in locale encoding, in such a
   way that comparing uN_normxfrm (S1) and uN_normxfrm (S2) with memcmp2() is
   equivalent to comparing S1 and S2 with uN_normcoll().
   NF must be either UNINORM_NFC or UNINORM_NFKC.  */
extern char *
       u8_normxfrm (const uint8_t *s, size_t n, uninorm_t nf,
                    char *resultbuf, size_t *lengthp);
extern char *
       u16_normxfrm (const uint16_t *s, size_t n, uninorm_t nf,
                     char *resultbuf, size_t *lengthp);
extern char *
       u32_normxfrm (const uint32_t *s, size_t n, uninorm_t nf,
                     char *resultbuf, size_t *lengthp);


/* Compare S1 and S2, ignoring differences in normalization, using the
   collation rules of the current locale.
   NF must be either UNINORM_NFC or UNINORM_NFKC.
   If successful, set *RESULT to -1 if S1 < S2, 0 if S1 = S2, 1 if S1 > S2, and
   return 0.  Upon failure, return the error number.  */
extern int
       u8_normcoll (const uint8_t *s1, size_t n1, const uint8_t *s2, size_t n2,
                    uninorm_t nf, int *result);
extern int
       u16_normcoll (const uint16_t *s1, size_t n1, const uint16_t *s2, size_t 
n2,
                     uninorm_t nf, int *result);
extern int
       u32_normcoll (const uint32_t *s1, size_t n1, const uint32_t *s2, size_t 
n2,
                     uninorm_t nf, int *result);