But i dont think this will scale very well... (and probably has subtle problems anyway)

One quibble is that because \d is a subset of \w then a string such as "abc123def" will get \w{9} in your version. Here's a slightly improved version (for some definition of improved) 

my $string=" \aabc123def!*#\n";
$string=~s{  ([[:digit:]]+)
            |([[:alpha:]]+)
            |([[:punct:]]+)
            |([[:space:]]+)
            |([[:cntrl:]]+)
            |(.)
          }
          {
              defined($1) ? '[[:digit:]]{'.length($1).'}'
                       : defined($2) ? '[[:alpha:]]{'.length($2).'}'
                       : defined($3) ? '[[:punct:]]{'.length($3).'}'
                       : defined($4) ? '[[:space:]]{'.length($4).'}'
                       : defined($5) ? '[[:cntrl:]]{'.length($5).'}'
                       : "\Q$+\E"  # anything else?
                                     
          }gex;
print $string;

[download]

But it still has problems (for example, \n is in both :space: and :cntrl: so "\n\a" produces [[:space:]]{1}[[:cntrl:]]{1}, but "\a\n" produces [[:cntrl:]]{2}).

In reply to Re: Re: Regular Expression Builder by Anonymous Monk
in thread Regular Expression Builder by Rich36

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