NAME
    Unicode::Towctrans - Generate small casefolding tables

SYNOPSIS
        gen_wctrans
        gen_wctrans -v 15
        gen_wctrans -v 15 --cf CaseFolding.txt.15 --out towctrans-15.h

DESCRIPTION
    gen_wctrans generates a towctrans.h header file, which is used by "musl"
    and "safeclib" to generate small and efficient case folding tables, to
    build the libc towupper() and towlower() functions and its secure
    variants towupper_s() and towlower_s().

    If you know that your iswalpha() works correctly (heavily locale
    dependent, mostly not), then use "--with_iswalpha" to get a much faster
    function. E.g. for benchmarking

    Planned also for the multi-byte folding tables for towfc().

    In work: Currently it passes all tests (more than glibc), but is way too
    slow.

PERFORMANCE
    Currently it is still a bit un-optimized, but small and fast enough with
    a working iswalpha().

        make -C examples
        ./bench
                my:        175 [us]
          musl-new:        250 [us]
          musl-old:        195 [us]
             glibc:        115 [us]

         wc -c towctrans-*.o
           3232 towctrans-my.o
           6024 towctrans-musl-new.o
           2520 towctrans-musl-old.o
            896 towctrans-glibc.o (but there needs to be the locale tables added)

INSTALLATION
    Perl 5.12 or later is required.

    This module does not need to be installed. running gen_wctrans is
    enough. However for full testing and global installation run this:

       perl Makefile.PL
       make
       make test
       make test-all
       sudo make install

DEPENDENCIES
    This module requires a CaseFolding.txt file from Unicode Character
    Database, which is automatically downloaded via wget.

AUTHOR
    Reini Urban <rurban@cpan.org>

    Copyright(C) 2026 Reini Urban. All rights reserved

COPYRIGHT AND LICENSE
    This module is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

    The generated files are MIT licensed. See the generated files headers.

SEE ALSO
    <https://www.unicode.org/reports/tr44/#Casemapping>
    <https://git.musl-libc.org/cgit/musl/tree/src/ctype/towctrans.c>
    <https://git.musl-libc.org/cgit/musl/tree/src/ctype/towctrans.c?id=e8aba
    58ab19a18f83d7f78e80d5e4f51e7e4e8a9>
    <https://github.com/rurban/safeclib/blob/master/src/extwchar/towctrans.c
    >
    <https://sourceware.org/git/?p=glibc.git;a=tree;f=wctype;;hb=HEAD>
