New M4 filter.

[lemzwerg]

The code is mainly taken from the cpp stuff, with suitable adaptions.

This is my first Perl code contribution ever; there might still be problems...

Grüße aus Wien :-)

[rurban]

Idea looks great. I'll check if the tests will really survive all architectures.

[lemzwerg]

Here's a sample that demonstrates its usage

http://repo.or.cz/wortliste.git/blob/HEAD:/skripte/perl/wl-new2old.pl

(it provides the M4 filtering code in a local module).

Using M4 instead of subroutines makes the script at least 20% faster. The German word list to be processed has almost 500000 lines which makes this significant.

In case you want to actually run the script: The input file can be generated with

skripte/umformatierung.py -k wortliste > wlst

[rurban]

I see, that's a convincing argument.

[rurban]

Thanks