For completeness, I'd have to mention Regexp::Common, in particular Regexp::Common::number, which allows you to use expressions like the following (lifted shamelessly from the 'DESCRIPTION'):

• $RE{num}{int}{-base}{-sep}{-group}{-places}
• $RE{num}{real}{-base}{-radix}{-places}{-sep}{-group}{-expon}
• $RE{num}{dec}{-radix}{-places}{-sep}{-group}{-expon}
• $RE{num}{oct}{-radix}{-places}{-sep}{-group}{-expon}
• $RE{num}{bin}{-radix}{-places}{-sep}{-group}{-expon}
• $RE{num}{hex}{-radix}{-places}{-sep}{-group}{-expon}
• $RE{num}{decimal}{-base}{-radix}{-places}{-sep}{-group}
• $RE{num}{square}
• $RE{num}{roman}