- added comments

- bugfix in peep_hole_optimizer(), \x00 should not be used, \x{00} prefered to avoid misinterpretations

lib/File/FormatIdentification/Pronom.pm

@@ -12,7 +12,7 @@ use YAML::XS;
 use File::FormatIdentification::Regex;
 use Moose;
 
-our $VERSION = '0.01';
+our $VERSION = '0.02';
 
 # Preloaded methods go here.
 # flattens a regex-structure to a regex-string, expects a signature-pattern and a list of regex-structures
@@ -109,10 +109,10 @@ sub _expand_pattern ($) {
     my $pattern = $_[0];
     $pattern =~ s/(?<=\[)!/^/g;
     $pattern =~ s/(?<=[0-9A-F]{2}):(?=[0-9A-F]{2})\]/-]/g;
-    $pattern =~ s/(?=[0-9A-F]{2})/\\x/g;
+    $pattern =~ s/([0-9A-F]{2})/\\x{$1}/g;
 
     # substitute hex with printable ASCII-Output
-    $pattern =~ s#\\x(3[0-9]|[46][1-9A-F]|[57][0-9A])#chr( hex($1) );#egs;
+    $pattern =~ s#\\x\{(3[0-9]|[46][1-9A-F]|[57][0-9A])\}#chr( hex($1) );#egs;
     return $pattern;
 } ## end sub _expand_pattern ($)
 

lib/File/FormatIdentification/Regex.pm

@@ -1,5 +1,5 @@
 package File::FormatIdentification::Regex;
-
+# helper module to combine and optimize regexes
 use 5.024001;
 use strict;
 use warnings;
@@ -87,7 +87,11 @@ sub hex_replace_from_bracket {
 
 sub peep_hole_optimizer ($) {
     my $regex = $_[0]; # only works if special Regexes within File::FormatIdentification:: used
-    $regex = hex_replace_to_bracket($regex);
+
+    #$regex = hex_replace_to_bracket($regex);
+    if ($regex =~ m/\\x[0-9]+/) {
+        confess "regex '$regex' has invalid \\x sequences, use \\x{} instead!";
+    }
     my $oldregex = $regex;
     ##### first optimize bracket-groups
     my $subrg =
@@ -198,15 +202,11 @@ sub peep_hole_optimizer ($) {
     #        say "Found in regex='$regex' sub='$sub' with matches=$matches";
     #        $regex =~ s#($subrg)\1{3,}(?!$subrg*\}#$sub\{$matches\}#;
     #}
-    #### restore \x{ff} to \xff
-    $regex = hex_replace_from_bracket($regex);
-    if ( $regex =~ m#\\x0\{# ) {
-        confess "wrong substitution of oldregex = \n\t'", $oldregex,
-          "'\n -> \n\t'", $regex, "'";
-    }
+
     return $regex;
 }
 
+# calc regex quality, if more specific the quality is higher
 sub calc_quality ($) {
     my $regex = shift;