NAME

       GraphViz2::Parse::Regexp - Visualize a Perl regular expression as a graph

SYNOPSIS

           use GraphViz2::Parse::Regexp;
           # no objects - quicker
           my $gd = GraphViz2::Parse::Regexp::to_graph('(([abcd0-9])|(foo))');

           # populate a GraphViz2 object with a Graph::Directed of a regexp
           my $gv = GraphViz2->from_graph(GraphViz2::Parse::Regexp::graphvizify($gd));

           # OO interface, using lazy-built attributes
           my $gvre = GraphViz2::Parse::Regexp->new(regexp => $regexp);
           my $gd = $gvre->as_graph; # Graph::Directed object
           # or supply a suitable Graph::Directed object
           my $gvre = GraphViz2::Parse::Regexp->new(as_graph => $gd);
           # then get the GraphViz2 object
           my $gv = $gvre->graph;

           # DEPRECATED ways to get $gvre with populated $gv
           my $gvre = GraphViz2::Parse::Regexp->new;
           $gvre->create(regexp => '(([abcd0-9])|(foo))');
           my $gv = $gvre->graph;
           # or give it a pre-set-up GraphViz2 object
           my $gv = GraphViz2->new(...);
           my $gvre = GraphViz2::Parse::Regexp->new(graph => $gv);
           # call ->create as above

           # produce a visualisation
           my $format = shift || 'svg';
           my $output_file = shift || "output.$format";
           $gv->run(format => $format, output_file => $output_file);

       See t/gen.parse.regexp.t.

DESCRIPTION

       Takes a Perl regular expression and converts it into a Graph::Directed object, or directly
       into a GraphViz2 object.

FUNCTIONS

       This is the recommended interface.

   to_graph
           my $gd = GraphViz2::Parse::Regexp::to_graph('(([abcd0-9])|(foo))');

       Given a Perl regular expression, returns a Graph::Directed object describing the finite
       state machine for it.

   graphvizify
           my $gv = GraphViz2->from_graph(GraphViz2::Parse::Regexp::graphvizify($gd));

       Mutates the given graph object to add to it the "graphviz" attributes visualisation
       "hints" that will make the "from_graph" in GraphViz2 method visualise this regular
       expression in the most meaningful way, including labels and groupings.

       It is idempotent as it simply sets the "graphviz" attribute of the relevant graph
       entities.

       Returns the graph object for convenience.

METHODS

       This is a Moo class, but with a recommended functional interface.

   Constructor attributes
       regexp

       The regular expression to use.

       This key is optional. You need to provide it by the time you access either the "as_graph"
       or "graph".

       as_graph

       The Graph::Directed object to use. If not given, will be lazily built on access, from the
       "regexp".

       graph

       The GraphViz2 object to use. This allows you to configure it as desired.

       This key is optional. If provided, the "create" method will populate it.  If not, it will
       have these defaults, lazy-built and populated from the "as_graph".

           my $gv = GraphViz2->new(
                   edge   => {color => 'grey'},
                   global => {directed => 1},
                   graph  => {rankdir => 'TB'},
                   node   => {color => 'blue', shape => 'oval'},
           );

   create(regexp => $regexp)
       DEPRECATED. Mutates the object to set the "regexp" attribute, then accesses the "as_graph"
       attribute (possibly lazy-building it), then "graphvizify"s its "as_graph" attribute with
       that information, then "from_graph"s its "graph".

       Returns $self for method chaining.

THANKS

       Many thanks are due to the people who chose to make Graphviz <http://www.graphviz.org/>
       Open Source.

       And thanks to Leon Brocard <http://search.cpan.org/~lbrocard/>, who wrote GraphViz, and
       kindly gave me co-maint of the module.

AUTHOR

       GraphViz2 was written by Ron Savage <ron@savage.net.au> in 2011.

       Home page: <http://savage.net.au/index.html>.

COPYRIGHT

       Australian copyright (c) 2011, Ron Savage.

       All Programs of mine are 'OSI Certified Open Source Software'; you can redistribute them
       and/or modify them under the terms of The Perl License, a copy of which is available at:
       http://dev.perl.org/licenses/