/ 
Unicode-Towctrans-0.02
/ Unicode::Towctrans

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=e8aba58ab19a18f83d7f78e80d5e4f51e7e4e8a9
https://github.com/rurban/safeclib/blob/master/src/extwchar/towctrans.c
https://sourceware.org/git/?p=glibc.git;a=tree;f=wctype;;hb=HEAD