graph_tools : printing tree

Author: Wandalen

module/move/graphs_tools/src/tree_print.rs

@@ -37,14 +37,66 @@ mod private
   {
 
     /// Print directed graph as a tree.
-    fn _print_as_tree< 'w >( &self, write : &'w mut ( dyn core::fmt::Write + 'w ), node : Self::NodeId ) -> fmt::Result
+    fn _print_as_tree< 'w >( &'g self, write : &'w mut ( dyn core::fmt::Write + 'w ), node_id : Self::NodeId ) -> fmt::Result
     {
-      // let node = self.node_ref( node );
-      write.write_fmt( format_args!( "{:?}", node ) )
+      #![ allow( non_upper_case_globals ) ]
+      use iter_tools::Itertools;
+      const _up_down : &str = "│  ";
+      const _up_down_right : &str = "├─ ";
+      const _left_right : &str = "─";
+      const _down_right : &str = "┌─";
+
+      let mut visited = collection_tools::HashSet::new();
+      let mut stack = collection_tools::Vec::new();
+
+      let prefix = | level : isize |
+      {
+        let left = if level > 0
+        {
+          std::iter::repeat( _up_down ).take( ( level - 1 ) as usize ).join( " " )
+        }
+        else
+        {
+          String::new()
+        };
+        let right = if level > 0
+        {
+          _up_down_right
+        }
+        else
+        {
+          &String::new()
+        };
+        return format!( "{}{}", left, right );
+      };
+
+      let push = | stack : &mut collection_tools::Vec< ( Self::NodeId, isize ) >, node_id, level |
+      {
+        println!( "push {:?} level:{}", node_id, level );
+        stack.push( ( node_id, level ) );
+      };
+
+      push( &mut stack, node_id, 0 );
+
+      while let Some( ( node_id, level ) ) = stack.pop()
+      {
+
+        if visited.insert( node_id )
+        {
+          write.write_fmt( format_args!( "{}{:?}\n", prefix( level ), node_id ) )?;
+
+          for child_id in self.node_out_nodes( node_id ).rev()
+          {
+            push( &mut stack, child_id, level + 1 );
+          }
+        }
+      }
+
+      return Ok( () )
     }
 
     /// Print directed graph as a tree.
-    fn print_as_tree< 'w >( &self, node : Self::NodeId ) -> String
+    fn print_as_tree< 'w >( &'g self, node : Self::NodeId ) -> String
     {
       // let node = self.node_ref( node );
       let mut result = String::new();

module/move/graphs_tools/tests/inc/graph/map_of_nodes.rs

@@ -157,4 +157,27 @@ impl Graph
     graph
   }
 
+  pub fn triplet_with_double_legs() -> Self
+  {
+
+    // Create nodes
+    let mut node0 = Node::new( 0 );
+    let mut node1 = Node::new( 1 );
+    let node2 = Node::new( 2 );
+    let mut node3 = Node::new( 3 );
+    let node4 = Node::new( 4 );
+    let node5 = Node::new( 5 );
+    let node6 = Node::new( 6 );
+    let node7 = Node::new( 7 );
+
+    node0.children_add([ &node1, &node2, &node3 ]);
+    node1.children_add([ &node4, &node5 ]);
+    node3.children_add([ &node6, &node7 ]);
+
+    let mut graph = Self::default();
+    graph.nodes_add([ node0, node1, node2, node3, node4, node5, node6, node7 ]);
+
+    graph
+  }
+
 }

module/move/graphs_tools/tests/inc/tree_print_test.rs

@@ -11,12 +11,27 @@ use graph::map_of_nodes::
 fn _print_as_tree()
 {
   use the_module::tree_print::GraphDirectedPrintAsTree;
-  let graph = Graph::duplet();
+  let graph = Graph::duplet_assymetric();
 
   let mut got = String::new();
-  let r = graph._print_as_tree( &mut got, 1.into() );
+  let r = graph._print_as_tree( &mut got, 0.into() );
   let exp = "node::1";
   assert_eq!( got, exp );
   assert!( r.is_ok() );
 
 }
+
+//
+
+#[ test ]
+fn print_as_tree()
+{
+  use the_module::tree_print::GraphDirectedPrintAsTree;
+  let graph = Graph::triplet_with_double_legs();
+
+  let got = graph.print_as_tree( 0.into() );
+  let exp = "node::1";
+  println!( "{}", got );
+  assert_eq!( got, exp );
+
+}