use strict;
use warnings;
use PDL::PP;
use Graph;
use GraphViz2;

my $g = Graph->new; # should really be hypergraph but GraphViz2 not do yet
for my $r (@{$PDL::PP::deftbl}) {
  for my $t (@{$r->{targets}}) {
    $g->add_edge($t, $_) for map s/_//gr, @{$r->{conditions}||[]};
  }
}
my ($fmt) = $ARGV[0] =~ /\.([^.]+)$/;
$g->set_graph_attribute(graphviz=>{graph=>{rankdir=>'LR'}});
GraphViz2->from_graph($g)->run(format=>$fmt,output_file=>$ARGV[0]);

=head1 NAME

doc-pp - Generate graph of pp_def key dependencies with graphviz

=head1 SYNOPSIS

  doc-pp deps.svg

=head1 DESCRIPTION

Uses L<Graph> and L<GraphViz2> to visualise the dependencies between
keys in L<PDL::PP/pp_def>.