15.4.783  src/lib/graph/printgraph.pkg

# printgraph.pkg
#  Print a graph 
#  -- Allen Leung

# Compiled by:
#     src/lib/graph/graphs.lib

###          "The wise speak only of what they know."
###
###                               -- Gandalf



stipulate
    package odg =  oop_digraph;                                         # oop_digraph   is from   src/lib/graph/oop-digraph.pkg
herein

    api Print_Graph {
        #
        to_string:  odg::Digraph(N,E,G) -> String;                      # Here N,E,G stand stead for the types of client-package-supplied records associated with (respectively) nodes, edges and graphs.
    };
end;



stipulate
    package odg =  oop_digraph;                                         # oop_digraph   is from   src/lib/graph/oop-digraph.pkg
herein

    package   print_graph
    : (weak)  Print_Graph                                               # Print_Graph           is from   src/lib/graph/printgraph.pkg
    {
        fun to_string (odg::DIGRAPH graph)
            =
            {   fun show_edges es
                    = 
                    string::cat  (map'  es  (\\ (i, j, _) =  int::to_string i + " -> " + int::to_string j + "\n"));

                fun show_nodes ns
                    = 
                    string::cat  (map' ns  (\\ n = int::to_string n + " ")) + "\n";

                graph.name + "\n" +
                    "nodes: " + show_nodes (map #1 (graph.nodes ())) + 
                    "edges:\n" + show_edges (graph.edges ()) + 
                    "entry edges:\n" + 
                        show_edges (list::cat (map (graph.entry_edges o #1) (graph.nodes ()))) +  
                    "exit edges:\n" + 
                        show_edges (list::cat (map (graph.exit_edges o #1) (graph.nodes ()))) +  
                    "entries: " + show_nodes (graph.entries ()) + 
                    "exits: " + show_nodes (graph.exits ());
            };
    };
end;