Are you looking for the /e option? (See perlre and perlretut). Here's an example, in action:

use 5.010_001;
use strict;
use warnings;

my $string = "It's hard to teach an old dog new tricks.";

$string =~ s/(dog)/reverse($1)/e;

say $string;
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The output: "It's hard to teach an old god new tricks." What's happening here is the right-hand side is being evaluated as code. The code should return a string which will serve as the replacement string.

I Tried to use a function in a replace regex

The second half of the substitution operator (s///) is just a string, not a regex.

One way to do it is:

$t =~ s/$somePattern/@{[ some_function($1) ]}/g;
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That would be the perfect way, if the /e modifier wasn't specifically designed to provide a means of executing code on the RHS of the s/// operator, without jumping through that hoop.




Dave

Not so perfect, in any event. Here's a snippet of a debugging session

  DB<1> $t = 'teach an old dog new tricks'

  DB<2> $t =~ s/(dog)/@{[ reverse($1) ]}/g

  DB<3> x $t
0  'teach an old dog new tricks'
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You'd have to do

$t =~ s/(dog)/@{[ scalar(reverse($1)) ]}/g
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