print $& if $var =~ /^[1-3]$/;

##</code><code>##

sub look_into {
   my $archetype= shift;
   eval 'sub { $_[0] =~ /$archetype/o; }'
}

my $is_text_am_too_red     = look_into q/\b(am|too|red)\b/;
my $single_digit_in_range  = look_into q/^[1-5]$/;
my $double_digit_in_set    = look_into q/^[5-7][49]$/;
# etc.

if($is_text_am_too_red    ->($_)){ print "get some sleep!" }
if($single_digit_in_range ->($_)){ print "single digit in range!" }
if($double_digit_in_set   ->($_)){ print "double digit in set!" }
#etc.