mostly implemented depth-first traversal

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/arel/nodes/node.rb b/lib/arel/nodes/node.rb
index 841b954db9..90c63f0be9 100644
--- a/lib/arel/nodes/node.rb
+++ b/lib/arel/nodes/node.rb
@@ -3,6 +3,8 @@ module Arel
     ###
     # Abstract base class for all AST nodes
     class Node
+      include Enumerable
+
       ###
       # Factory method to create a Nodes::Not node that has the recipient of
       # the caller as a child.
@@ -32,6 +34,11 @@ module Arel
         viz = Visitors.for engine
         viz.accept self
       end
+
+      # Iterate through AST, nodes will be yielded depth-first
+      def each &block
+        Visitors::DepthFirst.new(block).accept self
+      end
     end
   end
 end