| Subject: | Documentation for params to Graph::Traversal and control of Traversal starting node |
This is feature enhancement.
I've written some documentation describing the params to Graph::Traversal.
I've also added a few functions and their documentation to the Traversal object.
graph() - an accessor that just returns the stored graph, but is handy to have in callback functions like those that might be registered with successor
$S->travese_starting_at($v) - specifies a node to start the traversal from
$S->travese_single_component_starting_at($v); - specifies a node to start the traversal from and specifies that if the graph is partitioned, constrain the traversal to the component containing $v.
Only in Graph-0.20105-cmu/: Makefile
Only in Graph-0.20105-cmu/: blib
diff -r -c Graph-0.20105/lib/Graph/Traversal.pm Graph-0.20105-cmu/lib/Graph/Traversal.pm
*** Graph-0.20105/lib/Graph/Traversal.pm Sun Apr 4 16:19:45 2004
--- Graph-0.20105-cmu/lib/Graph/Traversal.pm Wed Jun 9 12:21:53 2004
***************
*** 3,8 ****
--- 3,10 ----
use strict;
local $^W = 1;
+ use Carp;
+
use Graph::Base;
use vars qw(@ISA);
***************
*** 38,44 ****
$dfs = Graph::DFS->new($G, %param)
$bfs = Graph::BFS->new($G, %param)
! I<%param documentation to be written>
=cut
--- 40,46 ----
$dfs = Graph::DFS->new($G, %param)
$bfs = Graph::BFS->new($G, %param)
! See below for %param documentation.
=cut
***************
*** 436,442 ****
--- 438,564 ----
=pod
+ =item graph
+
+ my $G = $S->graph();
+
+ Returns the graph object that the search is operating over.
+
+ =cut
+
+ sub graph {
+ my $S = shift;
+ my $G = $S->{ G };
+
+ return $G;
+ }
+
+ =pod
+
+ =item traverse_single_component_starting_at
+
+ $S->travese_single_component_starting_at($v);
+
+ Tell search object to begin traversal at vertex $v, and stop when all
+ vertices in the component containing $v have been traversed.
+
+ =cut
+
+ sub traverse_single_component_starting_at {
+ my $S = shift;
+ my $start_vertex = shift;
+
+ my $G = $S->{ G };
+
+
+ croak "'$start_vertex' not in graph" if (!$G->has_vertex($start_vertex));
+
+ $S->{param}->{get_next_root} =
+ sub {
+ return (exists $_[0]->{vertex_found}->{$start_vertex} ?
+ undef : $start_vertex)
+ }
+ }
+
+
+ =pod
+
+ =item traverse_starting_at
+
+ $S->travese_starting_at($v);
+
+ Tell search object to begin traversal at vertex $v. If there are
+ multiple components in the graph, the rest of the components will be
+ traversed starting at the node with highest degree.
+
+ =cut
+
+ sub traverse_starting_at {
+ my $S = shift;
+ my $start_vertex = shift;
+
+ my $G = $S->{ G };
+
+
+ croak "'$start_vertex' not in graph" if (!$G->has_vertex($start_vertex));
+
+ $S->{param}->{get_next_root} = $start_vertex;
+ }
+
+
+ =pod
+
=back
+
+ =head1 USING PARAMS TO CONTROL THE SEARCH
+
+ The following named parameters can be passed to new() when a search
+ object is created, or to some of the methods on the object.
+ Parameters passed to a method override the ones passed to new().
+
+ =head2 Controlling where the traversal starts
+
+ =over
+
+ =item get_next_root
+
+ Used the determine the root vertex for the traversal. If it is a code
+ reference, the result of running it with parameters ($S, %param) will
+ be the next root. Otherwise it is assumed to be the next root vertex
+ as it is.
+
+ See also C<traverse_starting_at()> and C<traverse_single_component_starting_at()>
+
+ =back
+
+ =head2 Invoking a callback as each edge is traversed
+
+ Each of the following parameters is assumed to be bound to a closure
+ that will be called at the respective time with the arguments
+ (From_vertex, To_vertex, Ref_to_Search_Object).
+
+ =over
+
+ =item successor
+
+ Called as each potential successor is expanded. Will be called once
+ for all reachable edges in graph.
+
+ =item unseen_successor
+
+ Called the first time vertex $v is found.
+
+ =item seen_successor
+
+ Called each subsequent time vertex $v is found.
+
+ =back
+
+ If there are multiple edges between $u and $v, either C<seen_sucessor>
+ or C<unseen_successo>r will be called for the first edge, depending on
+ whether $v has been visited before. C<seen_successor> will be called
+ once for each of the rest of the multiple edges.
+
=head1 COPYRIGHT
Only in Graph-0.20105-cmu/lib/Graph: Traversal.pm~
Only in Graph-0.20105-cmu/: pm_to_blib