perl-PPIx-Regexp

Parse regular expressions

The purpose of the _PPIx-Regexp_ package is to parse regular expressions in a manner similar to the way the PPI package parses Perl. This class forms the root of the parse tree, playing a role similar to PPI::Document. This package shares with PPI the property of being round-trip safe. That is, my $expr = 's/ ( \d+ ) ( \D+ ) /$2$1/smxg'; my $re = PPIx::Regexp->new( $expr ); print $re->content() eq $expr ? "yes\n" : "no\n" should print 'yes' for any valid regular expression. Navigation is similar to that provided by PPI. That is to say, things like 'children', 'find_first', 'snext_sibling' and so on all work pretty much the same way as in PPI. The class hierarchy is also similar to PPI. Except for some utility classes (the dumper, the lexer, and the tokenizer) all classes are descended from PPIx::Regexp::Element, which provides basic navigation. Tokens are descended from PPIx::Regexp::Token, which provides content. All containers are descended from PPIx::Regexp::Node, which provides for children, and all structure elements are descended from PPIx::Regexp::Structure, which provides beginning and ending delimiters, and a type. There are two features of PPI that this package does not provide - mutability and operator overloading. There are no plans for serious mutability, though something like PPI's 'prune' functionality might be considered. Similarly there are no plans for operator overloading, which appears to the author to represent a performance hit for little tangible gain.