#!/usr/bin/perl --
use Regexp::English;
print Regexp::English ->new
    ->remember
    ->multiple
    ->digit, "\n";
__END__
(?^:((?:\d+)))

##</code><code>##

my( @numbers ) = $str -~  m{ (\d+) }gx;

##</code><code>##

use YAPE::Regex::Explain;
print YAPE::Regex::Explain->new(
qr{ (\d+) }x,
)->explain;
__END__
The regular expression:

(?x-ims: (\d+) )

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?x-ims:                 group, but do not capture (disregarding
                         whitespace and comments) (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n):
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    \d+                      digits (0-9) (1 or more times (matching
                             the most amount possible))
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

##</code><code>##

$ perl -MRegexp::Common -e " print $RE{num}{int} "
(?:(?:[+-]?)(?:[0123456789]+))

##</code><code>##

#!/usr/bin/perl --
use strict; use warnings;
my $REint = qr{
#----------------------------------------------------------------------
  (?:                  #    group, but do not capture:
#----------------------------------------------------------------------
    (?:                #      group, but do not capture:
#----------------------------------------------------------------------
      [+-]?            #        any character of: '+', '-' (optional
                       #        (matching the most amount possible))
#----------------------------------------------------------------------
    )                  #      end of grouping
#----------------------------------------------------------------------
    (?:                #      group, but do not capture:
#----------------------------------------------------------------------
      [0123456789]+    #        any character of: '0', '1', '2', '3',
                       #        '4', '5', '6', '7', '8', '9' (1 or
                       #        more times (matching the most amount
                       #        possible))
#----------------------------------------------------------------------
    )                  #      end of grouping
#----------------------------------------------------------------------
  )                    #    end of grouping
#----------------------------------------------------------------------
}x; # end of qr

print "$_\n" for "1 plus 1 is 2" =~ m/$REint/g
__END__
1
1
2