- improved regex a little bit using look-behind

- improved regex a little bit using look-ahead
- avoiding shift

lib/File/FormatIdentification/Regex.pm

@@ -53,19 +53,18 @@ sub or_combine (@) {
 }
 
 sub simplify_two_or_combined_regex($$) {
-    my $rx1    = shift;
-    my $rx2    = shift;
+    my $rx1    = $_[0];
+    my $rx2    = $_[1];
     my $common = "";
+    my $rx = qr#\(([A-Za-z0-9]*)\)#;
     if (
         #        ($rx1 =~ m#\(([A-Za-z0-9]*)|(\\x[0-9A-F]{2})*\)#) &&
         #       ($rx2 =~ m#\(([A-Za-z0-9]*)|(\\x[0-9A-F]{2})*\)#)
-        ( $rx1 =~ m#\(([A-Za-z0-9]*)\)# )
-        && ( $rx2 =~ m#\(([A-Za-z0-9]*)\)# )
-
+        ( $rx1 =~ m/$rx/ ) and ( $rx2 =~ m/$rx/ )
       )
     {
         # only left simplify supported yet
-        my $common = String::LCSS::lcss( $rx1, $rx2 );
+        $common = String::LCSS::lcss( $rx1, $rx2 );
 
         #say "";
         #say "Found common='$common' of rx1='$rx1' rx2='$rx2'";
@@ -76,19 +75,18 @@ sub simplify_two_or_combined_regex($$) {
 
 sub hex_replace_to_bracket {
     my $regex = shift;
-    $regex =~ s#\\x([0-9A-F]{2})#\\x{$1}#g;
+    $regex =~ s#(?<=\\x)([0-9A-F]{2})#{$1}#g;
     return $regex;
 }
 
 sub hex_replace_from_bracket {
     my $regex = shift;
-    $regex =~ s#\\x\{([0-9A-F]{2})\}#\\x$1#g;
+    $regex =~ s#(?<=\\x)\{([0-9A-F]{2})\}#$1#g;
     return $regex;
 }
 
 sub peep_hole_optimizer ($) {
-    my $regex = shift
-      ; # only works if special Regexes within File::FormatIdentification:: used
+    my $regex = $_[0]; # only works if special Regexes within File::FormatIdentification:: used
     $regex = hex_replace_to_bracket($regex);
     my $oldregex = $regex;
     ##### first optimize bracket-groups