NAME
Grammar::Graph::Simplify  Simplify Grammar::Graph objects
SYNOPSIS
use Grammar::Graph;
use Grammar::Graph::Simplify;
my $g = Grammar::Graph>from_grammar_formal($formal);
...
$g>fa_merge_equivalent_vertices($start_vertex, $final_vertex);
DESCRIPTION
Extension methods for Grammar::Graph objects that simplify Grammars when possible.
METHODS
fa_merge_equivalent_vertices($start_vertex, $final_vertex)

This method is added to Grammar::Graph objects and when called it attempts to merge equivalent vertices in the object between the given
$start_vertex
and$final_vertex
. Ideally, the start vertex does not have incoming edges, and the final vertex does not have outgoing edges. The code is untested for when they do. It relies on being able to determine whether two labeled vertices have an equivalent label and there is currently no extension functionality to consider any but the standard labels. It dies when there are unrecognised labels. For the sentinel labelsGrammar::Graph::Prefix
andGrammar::Graph::Suffix
vertices are merged only when matching pairs are equivalent.The code relies on the
link
attributes of sentinel labels to determine which pairs are matching pairs, but then does not make any attempt to correct thelink
attributes, so it can be run only once on a given Grammar::Graph object. The code dies if an attempt is made to run the method a second time (it uses a graph attribute to maintain this state).
EXPORTS
None.
AUTHOR / COPYRIGHT / LICENSE
Copyright (c) 2014 Bjoern Hoehrmann <bjoern@hoehrmann.de>.
This module is licensed under the same terms as Perl itself.