From: tla <tla@mit.edu>
Date: Tue, 31 May 2011 12:13:40 +0000 (+0200)
Subject: CollateX version of GraphML parsing
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=cda6a45b9b206364ffe567844cbfa1d80697fd81;p=scpubgit%2Fstemmatology.git

CollateX version of GraphML parsing
---

diff --git a/lib/Text/Tradition/Parser/CollateX.pm b/lib/Text/Tradition/Parser/CollateX.pm
new file mode 100644
index 0000000..2c13921
--- /dev/null
+++ b/lib/Text/Tradition/Parser/CollateX.pm
@@ -0,0 +1,145 @@
+package Text::Tradition::Parser::CollateX;
+
+use strict;
+use warnings;
+use Text::Tradition::Parser::GraphML;
+
+=head1 NAME
+
+Text::Tradition::Parser::CollateX
+
+=head1 DESCRIPTION
+
+Parser module for Text::Tradition, given a GraphML file from the
+CollateX program that describes a collation graph.  For further
+information on the GraphML format for text collation, see
+http://gregor.middell.net/collatex/
+
+=head1 METHODS
+
+=over
+
+=item B<parse>
+
+parse( $graph, $graphml_string );
+
+Takes an initialized Text::Tradition::Graph object and a string
+containing the GraphML; creates the appropriate nodes and edges on the
+graph.
+
+=cut
+
+my $IDKEY = 'number';
+my $CONTENTKEY = 'token';
+my $TRANSKEY = 'identical';
+
+sub parse {
+    my( $tradition, $graphml_str ) = @_;
+    my $graph_data = Text::Tradition::Parser::GraphML::parse( $graphml_str );
+    my $collation = $tradition->collation;
+    my %witnesses; # Keep track of the witnesses we encounter as we
+                   # run through the graph data.
+
+    # Add the nodes to the graph.  First delete the start node, because
+    # GraphML graphs will have their own start nodes.
+    $collation->del_reading( $collation->start() );
+
+    my $extra_data = {}; # Keep track of info to be processed after all
+                         # nodes have been created
+    foreach my $n ( @{$graph_data->{'nodes'}} ) {
+	my %node_data = %$n;
+	my $nodeid = delete $node_data{$IDKEY};
+	my $token = delete $node_data{$CONTENTKEY};
+	unless( $nodeid && $token ) {
+	    warn "Did not find an ID or token for graph node, can't add it";
+	    next;
+	}
+	my $gnode = $collation->add_reading( $nodeid );
+	$gnode->text( $token );
+
+	# Whatever is left is extra info to be processed later.
+	if( keys %node_data ) {
+	    $extra_data->{$nodeid} = \%node_data;
+	}
+    }
+	
+    # Now add the edges.
+    foreach my $e ( @{$graph_data->{'edges'}} ) {
+	my %edge_data = %$e;
+	my $from = delete $edge_data{'source'};
+	my $to = delete $edge_data{'target'};
+
+	# In CollateX, we have a distinct witness data ID per witness,
+	# so that we can have multiple witnesses per edge.  We want to
+	# translate this to one witness per edge in our own
+	# representation.
+	foreach my $ekey ( keys %edge_data ) {
+	    my $wit = $edge_data{$ekey};
+	    # Create the witness object if it does not yet exist.
+	    unless( $witnesses{$wit} ) {
+		$tradition->add_witness( 'sigil' => $wit );
+		$witnesses{$wit} = 1;
+	    }
+	    $collation->add_path( $from->{$IDKEY}, $to->{$IDKEY}, $wit );
+	}
+    }
+
+    # Process the extra node data if it exists.
+    foreach my $nodeid ( keys %$extra_data ) {
+	my $ed = $extra_data->{$nodeid};
+	if( exists $ed->{$TRANSKEY} ) {
+	    
+	    my $tn_reading = $collation->reading( $nodeid );
+	    my $main_reading = $collation->reading( $ed->{$TRANSKEY} );
+	    if( $collation->linear ) {
+		$tn_reading->set_identical( $main_reading );
+	    } else {
+		$collation->merge_readings( $main_reading, $tn_reading );
+	    }
+	} # else we don't have any other tags to process yet.
+    }
+
+    # Find the beginning and end nodes of the graph.  The beginning node
+    # has no incoming edges; the end node has no outgoing edges.
+    my( $begin_node, $end_node );
+    foreach my $gnode ( $collation->readings() ) {
+	# print STDERR "Checking node " . $gnode->name . "\n";
+	my @outgoing = $gnode->outgoing();
+	my @incoming = $gnode->incoming();
+
+	unless( scalar @incoming ) {
+	    warn "Already have a beginning node" if $begin_node;
+	    $begin_node = $gnode;
+	    $collation->start( $gnode );
+	}
+	unless( scalar @outgoing ) {
+	    warn "Already have an ending node" if $end_node;
+	    $end_node = $gnode;
+	}
+    }
+
+    # Record for each witness its sequence of readings, and determine
+    # the common nodes.
+    my @common_nodes = $collation->walk_witness_paths( $end_node );
+
+    # Now we have added the witnesses and their paths, so have also
+    # implicitly marked the common nodes. Now we can calculate their
+    # explicit positions.
+    $collation->calculate_positions( @common_nodes );
+}
+    
+=back
+
+=head1 LICENSE
+
+This package is free software and is provided "as is" without express
+or implied warranty.  You can redistribute it and/or modify it under
+the same terms as Perl itself.
+
+=head1 AUTHOR
+
+Tara L Andrews, aurum@cpan.org
+
+=cut
+
+1;