#!/usr/bin/perl -w

use strict;
use warnings;
                                                                            
my @views = (
    "ignore",
    "abbbbc",
    "mn123op",
    "ignore",
    "uvwxy",
);

my %functions_hash = (
    'ab+c$' => [ 'b+',    'x' ],
    'mn\d+' => [ '(\d+)', '<number>' ],
    'uvwxy' => [ 'uvw',   'UVW' ],
);

foreach my $data (@views)
{
   while (my ($key, $pvalue) = each %functions_hash)
   {
      if ($data =~ /$key/)
      {
          my ($from, $to) = ($pvalue->[0], $pvalue->[1]);
          $data =~ s/$from/$to/;
          print "data is now $data\n";
      }
   }
}

##</code><code>##

data is now axc
data is now mn<number>op
data is now UVWxy