NAME

       "Devel::MAT::Graph" - a set of references between related SVs

DESCRIPTION

       Instances of this class represent an entire graph of references between related SVs, as a
       helper method for return values from various Devel::MAT methods, which might be used for
       some sort of screen layout or other analysis tasks.

CONSTRUCTOR

   new
          $graph = Devel::MAT::Graph->new( $dumpfile )

       Constructs a new "Devel::MAT::Graph" instance backed by the given dumpfile (which is only
       actually used to make the "$node->sv" method work).

MUTATION METHODS

   add_sv
          $graph->add_sv( $sv )

       Makes the graph aware of the given Devel::MAT::SV. This is not strictly necessary before
       calling "add_ref" or "add_root", but ensures that "has_sv" will return true immediately
       after it, and so can be used as a sentinel for recursion control.

   add_ref
          $graph->add_ref( $from_sv, $to_sv, $desc )

       Adds an edge to the graph, from and to the given SVs, with the given description.

   add_root
          $graph->add_root( $from_sv, $desc )

       Adds a root edge to the graph, at the given SV with the given description.

QUERY METHODS

   has_sv
          $bool = $graph->has_sv( $sv )

       Returns true if the graph has edges or roots for the given SV, or it has at least been
       given to "add_sv".

   get_sv_node
          $node = $graph->get_sv_node( $sv )

       Returns a "Node" object for the given SV.

   get_root_nodes
          @desc_nodes = $graph->get_root_nodes

       Returns an even-sized list of pairs, containing root descriptions and the nodes having
       those roots, in no particular order.

NODE OBJECTS

       The values returned by "get_sv_node" respond to the following methods:

   graph
          $graph = $node->graph

       Returns the containing "Devel::MAT::Graph" instance.

   addr
          $addr = $node->addr

       Returns the address of the SV represented by this node.

   sv
          $sv = $node->sv

       Returns the SV object itself, as taken from the dumpfile instance.

   roots
          @roots = $node->roots

       Returns any root descriptions given (by calls to "$graph->add_root" for the SV at this
       node.

          $graph->add_root( $sv, $desc );

          ( $desc, ... ) = $graph->get_sv_node( $sv )->roots

   edges_out
          @edges = $node->edges_out

       Returns an even-sized list of any edge descriptions and more "Node" objects given as
       references (by calls to "$graph->add_ref") from the SV at this node.

          $graph->add_ref( $from_sv, $to_sv, $desc )

          ( $desc, $to_edge, ... ) = $graph->get_sv_node( $from_sv )->edges_out

   edges_out (scalar)
          $n_edges = $node->edges_out

       In scalar context, returns the number of edges that exist; i.e. half the size of the
       pairlist that would be returned in list context.

   edges_in
          @edges = $node->edges_in

       Similar to "edges_out", but returns edges in the opposite direction; i.e.  edges of
       references to this node.

          $graph->add_ref( $from_sv, $to_sv, $desc )

          ( $desc, $from_edge, ... ) = $graph->get_sv_node( $to_sv )->edges_in

   edges_in (scalar)
          $n_edges = $node->edges_out

       In scalar context, returns the number of edges that exist; i.e. half the size of the
       pairlist that would be returned in list context.

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>