descendants はブロックを受けとらなくていい

Author: akicho8

lib/tree_support/treeable.rb

@@ -17,12 +17,12 @@ def each_node(&block)
       each {|node| node.each_node(&block)}
     end
 
-    def descendants(&block)
-      return enum_for(__method__) unless block_given?
-      each do |node|
-        yield node
-        node.descendants(&block)
-      end
+    def descendants
+      flat_map { |node| [node] + node.descendants }
+    end
+
+    def self_and_descendants
+      [self] + descendants
     end
 
     def ancestors
@@ -46,7 +46,7 @@ def root?
     end
 
     def leaf?
-      children.size.zero?
+      children.empty?
     end
   end
 end

test/test_treeable.rb

@@ -24,6 +24,10 @@ class TestTreeable < Test::Unit::TestCase
     assert_equal ["a", "a1", "a2", "x", "a3"], @root.descendants.collect(&:name)
   end
 
+  test "self_and_descendants" do
+    assert_equal ["*root*", "a", "a1", "a2", "x", "a3"], @root.self_and_descendants.collect(&:name)
+  end
+
   test "each_node" do
     assert_equal ["*root*", "a", "a1", "a2", "x", "a3"], @root.each_node.collect(&:name)
   end