NAME

       PPIx::Regexp::Node - Represent a container

SYNOPSIS

        use PPIx::Regexp::Dumper;
        PPIx::Regexp::Dumper->new( 'qr{(foo)}' )->print();

INHERITANCE

       "PPIx::Regexp::Node" is a PPIx::Regexp::Element.

       "PPIx::Regexp::Node" is the parent of PPIx::Regexp, PPIx::Regexp::Node::Range and
       PPIx::Regexp::Structure.

DESCRIPTION

       This class represents a structural element that contains other classes.  It is an abstract
       class, not instantiated by the lexer.

METHODS

       This class provides the following public methods. Methods not documented here are private,
       and unsupported in the sense that the author reserves the right to change or remove them
       without notice.

   child
        my $kid = $node->child( 0 );

       This method returns the child at the given index. The indices start from zero, and
       negative indices are from the end of the list, so that "$node->child( -1 )" returns the
       last child of the node.

   children
       This method returns the children of the Node. If called in scalar context it returns the
       number of children.

   contains
        print $node->contains( $elem ) ? "yes\n" : "no\n";

       This method returns true if the given element is contained in the node, or false
       otherwise.

   elements
       This method returns the elements in the Node. For a "PPIx::Regexp::Node" proper, it is the
       same as "children()".

   find
        my $rslt = $node->find( 'PPIx::Regexp::Token::Literal' );
        my $rslt = $node->find( 'Token::Literal' );
        my $rslt = $node->find( sub {
            return $_[1]->isa( 'PPIx::Regexp::Token::Literal' )
                && $_[1]->ordinal < ord(' ');
            } );

       This method finds things.

       If given a string as argument, it is assumed to be a class name (possibly without the
       leading 'PPIx::Regexp::'), and all elements of the given class are found.

       If given a code reference, that code reference is called once for each element, and passed
       $self and the element. The code should return true to accept the element, false to reject
       it, and ( for subclasses of "PPIx::Regexp::Node") "undef" to prevent recursion into the
       node. If the code throws an exception, you get nothing back from this method.

       Either way, the return is a reference to the list of things found, a false (but defined)
       value if nothing was found, or "undef" if an error occurred.

   find_parents
        my $rslt = $node->find_parents( sub {
            return $_[1]->isa( 'PPIx::Regexp::Token::Operator' )
                && $_[1]->content() eq '|';
            } );

       This convenience method takes the same arguments as "find", but instead of the found
       objects themselves returns their parents. No parent will appear more than once in the
       output.

       This method returns a reference to the array of parents if any were found. If no parents
       were found the return is false but defined. If an error occurred the return is "undef".

   find_first
       This method has the same arguments as "find", but returns either a reference to the first
       element found, a false (but defined) value if no elements were found, or "undef" if an
       error occurred.

   first_element
       This method returns the first element in the node.

   last_element
       This method returns the last element in the node.

   perl_version_introduced
       This method returns the maximum value of "perl_version_introduced" returned by any of its
       elements. In other words, it returns the minimum version of Perl under which this node is
       valid. If there are no elements, 5.000 is returned, since that is the minimum value of
       Perl supported by this package.

   perl_version_removed
       This method returns the minimum defined value of "perl_version_removed" returned by any of
       the node's elements. In other words, it returns the lowest version of Perl in which this
       node is "not" valid. If there are no elements, or if no element has a defined
       "perl_version_removed", "undef" is returned.

   schild
       This method returns the significant child at the given index; that is, "$node->schild(0)"
       returns the first significant child, "$node->schild(1)" returns the second significant
       child, and so on.  Negative indices count from the end.

   schildren
       This method returns the significant children of the node.

SUPPORT

       Support is by the author. Please file bug reports at <http://rt.cpan.org>, or in
       electronic mail to the author.

AUTHOR

       Thomas R. Wyant, III wyant at cpan dot org

COPYRIGHT AND LICENSE

       Copyright (C) 2009-2018 by Thomas R. Wyant, III

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl 5.10.0. For more details, see the full text of the licenses in the directory
       LICENSES.

       This program is distributed in the hope that it will be useful, but without any warranty;
       without even the implied warranty of merchantability or fitness for a particular purpose.