From 2280f0e465d582bbf9b895eba20c96abe77abaff Mon Sep 17 00:00:00 2001
From: Hiroshi Kono <hiroshi.kono@gmail.com>
Date: Sat, 12 Jun 2010 19:15:12 +0900
Subject: [PATCH] p.163 Change the parameter of  "count_descendants_matching"
 to block.

---
 chapter6/Extract_Surrounding_Method.rb | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/chapter6/Extract_Surrounding_Method.rb b/chapter6/Extract_Surrounding_Method.rb
index b9bd2d0..25a67ce 100644
--- a/chapter6/Extract_Surrounding_Method.rb
+++ b/chapter6/Extract_Surrounding_Method.rb
@@ -20,7 +20,7 @@ def number_of_living_descendants
   end
   
   def number_of_descendants_named(name)
-    count_descendants_matching(name)
+    count_descendants_matching{|descendant| descendant.name == name}
   end
   
   def alive?
@@ -28,10 +28,10 @@ def alive?
   end
   
   protected
-  def count_descendants_matching(name)
+  def count_descendants_matching(&block)
     children.inject(0) do |count, child|
-      count += 1 if child.name == name
-      count += child.count_descendants_matching(name)
+      count += 1 if yield child
+      count += child.count_descendants_matching(&block)
     end
   end
 end