* ext/psych/lib/psych/nodes/node.rb: Make Psych::Nodes::Node

  enumerable.
* ext/psych/lib/psych/visitors/depth_first.rb: Add a depth-first
  visitor to enumerate over a YAML AST in a depth-first fashion
* test/psych/nodes/test_enumerable.rb: test for enumerating nodes
* test/psych/visitors/test_depth_first.rb: test for depth-first
  visitor

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30624 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 0 deletions

diff --git a/ext/psych/lib/psych/nodes/node.rb b/ext/psych/lib/psych/nodes/node.rb
index bfd91f99ec..7c040ec463 100644
--- a/ext/psych/lib/psych/nodes/node.rb
+++ b/ext/psych/lib/psych/nodes/node.rb
@@ -6,6 +6,8 @@ module Psych
     # The base class for any Node in a YAML parse tree.  This class should
     # never be instantiated.
     class Node
+      include Enumerable
+
       # The children of this node
       attr_reader :children
 
@@ -18,6 +20,14 @@ module Psych
       end
 
       ###
+      # Iterate over each node in the tree. Yields each node to +block+ depth
+      # first.
+      def each &block
+        return enum_for :each unless block_given?
+        Visitors::DepthFirst.new(block).accept self
+      end
+
+      ###
       # Convert this node to Ruby.
       #
       # See also Psych::Visitors::ToRuby