Hello Regexp Alcolytes!

Disclaimer: Don't point me to Math::Roman, read the node. :-)

Probably the title of this node is horribly wrong, so I try to explain my need in more detail. Let's say you have a set of regexps. Now lets say you are testing each of these regexps against a string to see if it matches or not. Something like this Roman Numeral Thingie. Meanwhile it looks slightly better: 

              if($str =~ s/XLVIII$/IL/    or
                 $str =~ s/VIII$/IX/      or
                 $str =~ s/III$/IV/       or
                 $str =~ s/DCCCXCIX$/CM/  or
                 $str =~ s/CCCXCIX$/CD/   or

                 $str =~ s/LXXXIX$/XC/    or
                 $str =~ s/XXXIX$/XL/     or


                 $str =~ s/(I{1,2})$/$1I/ or

                 $str =~ s/CDXCIX$/D/     or
                 $str =~ s/CMXCIX$/M/     or
                 $str =~ s/XCIX$/C/       or

                 $str =~ s/I([VXLCDM])$/$1/ or
                 $str =~ s/([VXLCDM])$/$1I/) { }

              return $str;

[download]
And now there is a subroutine to answer the question if a given string actually is a roman numeral: 
              if($str !~ /[IVXLCDM]+/         ||
                 $str =~ /([IXC])\1{3,}/      ||
                 $str =~ /([VLD])\1{1,}/  ||

                 $str =~ /I[VXLCDM][IVXLCDM]/ ||
                 $str =~ /V[XLCDM][VXLCDM]/   ||
                 $str =~ /L[CDM][LCDM]/       ||
                 $str =~ /X[LCDM][XLCDM]/     ||
                 $str =~ /C[DM][CDM]/         ||
                 $str =~ /DM[DM]/) {
                  return 0;
              }

              return 1;

[download]
So lets return to the question. Given a set of regexps and given a wanted logical concatenation (lets start with AND,OR) of these regexps, is there any mechanism to create a smaller, more eficient set of regexps that will have the same effect?

I feel remembered to a similar problem in boolean logic, where you apply some de morgan, do transformations on complex boolean formulae and - sometimes - end up with smaller nifty formulae. Thought same should be possible with regexps.

Thoughts? Answers? Meditation?

Bye
 PetaMem

In reply to A Regexp Assembler/Compiler by PetaMem

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