package GraphViz2::Parse::RecDescent;
use strict;
use warnings;
use warnings qw(FATAL utf8); # Fatalize encoding glitches.
use GraphViz2;
use Moo;
use Parse::RecDescent;
has graph =>
(
default => sub{return ''},
is => 'rw',
#isa => 'GraphViz2',
required => 0,
);
our $VERSION = '2.46';
# -----------------------------------------------
sub BUILD
{
my($self) = @_;
$self -> graph
(
$self -> graph ||
GraphViz2 -> new
(
edge => {color => 'grey'},
global => {directed => 1},
graph => {rankdir => 'TB'},
logger => '',
node => {color => 'blue', shape => 'oval'},
)
);
} # End of BUILD.
# -----------------------------------------------
sub create
{
my($self, %arg) = @_;
my($parser) = $arg{grammar};
if (ref($parser) ne 'Parse::RecDescent')
{
$parser = Parse::RecDescent -> new($parser) || die 'Error: Faulty grammar';
}
$self -> graph -> add_node(name => $arg{name});
my($type, $text);
# A grammar consists of rules.
for my $rule (keys %{$$parser{rules} })
{
my($rule_label) = '';
# A rule consists of productions.
for my $production (@{$$parser{rules}{$rule}{prods} })
{
my($production_text) = '';
# A production consists of items.
for my $item (@{$$production{items} })
{
$type = ref $item;
$type =~ s/^Parse::RecDescent:://;
next if ($type eq 'Action');
if ($type =~ /^(?:Directive|UncondReject)$/)
{
$text = $$item{name};
}
elsif ($type eq 'Error')
{
$text = $$item{msg} ? "<error: $$item{msg}>" : '<error>';
}
elsif ($type =~ /^(?:Literal|Token|InterpLit)$/)
{
$text = $$item{description};
}
elsif ($type eq 'Operator')
{
$text = $$item{expected};
}
elsif ($type eq 'Repetition')
{
$text = "$$item{subrule}($$item{repspec})";
}
elsif ($type eq 'Subrule')
{
$text = $$item{subrule};
$text .= $$item{argcode} if (defined $$item{argcode});
}
else
{
$text = "Unknown: <$text>";
}
# Replace newlines with \n sequences to stop dot choking.
$text =~ s/\n/\\\\n/g;
$production_text .= "$text ";
} # End of $item.
$rule_label .= "$production_text ";
} # End of production.
$self -> graph -> add_node(name => $rule, label => $rule_label);
# Make links to the rules called.
for my $called (@{$$parser{rules}{$rule}{calls} })
{
$self -> graph -> add_edge(from => $rule, to => $called);
}
$self -> graph -> add_edge(from => $arg{name}, to => $rule);
} # End of rule.
return $self;
} # End of create.
# -----------------------------------------------
1;
=pod
=head1 NAME
L<GraphViz2::Parse::RecDescent> - Visualize a Parse::RecDescent grammar as a graph
=head1 Synopsis
#!/usr/bin/env perl
use strict;
use warnings;
use File::Spec;
use GraphViz2;
use GraphViz2::Parse::RecDescent;
use Log::Handler;
use Parse::RecDescent;
use File::Slurp; # For read_file().
# ------------------------------------------------
my($logger) = Log::Handler -> new;
$logger -> add
(
screen =>
{
maxlevel => 'debug',
message_layout => '%m',
minlevel => 'error',
}
);
my($graph) = GraphViz2 -> new
(
edge => {color => 'grey'},
global => {directed => 1},
graph => {rankdir => 'TB'},
logger => $logger,
node => {color => 'blue', shape => 'oval'},
);
my($g) = GraphViz2::Parse::RecDescent -> new(graph => $graph);
my $grammar = read_file(File::Spec -> catfile('t', 'sample.recdescent.1.dat') );
my($parser) = Parse::RecDescent -> new($grammar);
$g -> create(name => 'Grammar', grammar => $parser);
my($format) = shift || 'svg';
my($output_file) = shift || File::Spec -> catfile('html', "parse.recdescent.$format");
$graph -> run(format => $format, output_file => $output_file);
See scripts/parse.recdescent.pl (L<GraphViz2/Scripts Shipped with this Module>).
=head1 Description
Takes a L<Parse::RecDescent> grammar and converts it into a graph.
You can write the result in any format supported by L<Graphviz|http://www.graphviz.org/>.
Here is the list of L<output formats|http://www.graphviz.org/content/output-formats>.
=head1 Distributions
This module is available as a Unix-style distro (*.tgz).
See L<http://savage.net.au/Perl-modules/html/installing-a-module.html>
for help on unpacking and installing distros.
=head1 Installation
Install L<GraphViz2> as you would for any C<Perl> module:
Run:
cpanm GraphViz2
or run:
sudo cpan GraphViz2
or unpack the distro, and then either:
perl Build.PL
./Build
./Build test
sudo ./Build install
or:
perl Makefile.PL
make (or dmake or nmake)
make test
make install
=head1 Constructor and Initialization
=head2 Calling new()
C<new()> is called as C<< my($obj) = GraphViz2::Parse::RecDescent -> new(k1 => v1, k2 => v2, ...) >>.
It returns a new object of type C<GraphViz2::Parse::RecDescent>.
Key-value pairs accepted in the parameter list:
=over 4
=item o graph => $graphviz_object
This option specifies the GraphViz2 object to use. This allows you to configure it as desired.
The default is GraphViz2 -> new. The default attributes are the same as in the synopsis, above,
except for the logger of course, which defaults to ''.
This key is optional.
=back
=head1 Methods
=head2 create(name => $name, grammar => $grammar)
Creates the graph, which is accessible via the graph() method, or via the graph object you passed to new().
Returns $self for method chaining.
$name is the string which will be placed in the root node of the tree.
$grammar is either a L<Parse::RecDescent> object or a grammar. If it's a grammar, the code will
fabricate an object of type L<Parse::RecDescent>.
=head2 graph()
Returns the graph object, either the one supplied to new() or the one created during the call to new().
=head1 FAQ
See L<GraphViz2/FAQ> and L<GraphViz2/Scripts Shipped with this Module>.
=head1 Thanks
Many thanks are due to the people who chose to make L<Graphviz|http://www.graphviz.org/> Open Source.
And thanks to L<Leon Brocard|http://search.cpan.org/~lbrocard/>, who wrote L<GraphViz>, and kindly gave me co-maint of the module.
=head1 Version Numbers
Version numbers < 1.00 represent development versions. From 1.00 up, they are production versions.
=head1 Machine-Readable Change Log
The file Changes was converted into Changelog.ini by L<Module::Metadata::Changes>.
=head1 Support
Email the author, or log a bug on RT:
L<https://rt.cpan.org/Public/Dist/Display.html?Name=GraphViz2>.
=head1 Author
L<GraphViz2> was written by Ron Savage I<E<lt>ron@savage.net.auE<gt>> in 2011.
Home page: L<http://savage.net.au/index.html>.
=head1 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/
=cut