From a0826ed9f0dcfd9b7c831fa17114818c63898176 Mon Sep 17 00:00:00 2001
From: Joe Zhao <ztuowen@gmail.com>
Date: Thu, 20 Mar 2014 13:39:18 +0800
Subject: add while

---
 simple/simple.rb | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/simple/simple.rb b/simple/simple.rb
index a31e001..a045347 100644
--- a/simple/simple.rb
+++ b/simple/simple.rb
@@ -178,7 +178,27 @@ class Sequence < Struct.new(:first, :second)
       else
         reduced_first, reduced_environment = first.reduce(environment)
         [Sequence.new(reduced_first, second), reduced_environment]
+    end
+  end
+end
+
+class While < Struct.new(:condition,:body)
+  def to_s
+    "while (#{condition} { #{body} })"
+  end
+
+  def inspect
+    "<#{self}>"
+  end
+
+  def reducible?
+    true
+  end
+  
+  def reduce(environment)
+    [If.new(condition,Sequence.new(body,self),DoNothing.new), environment]
   end
+end
 
 class Machine < Struct.new(:statement, :environment)
   def step
-- 
cgit v1.2.3-70-g09d2