examples/stack.rb in armin-joellenbeck-rdbc-0.0.5 vs examples/stack.rb in armin-joellenbeck-rdbc-0.0.6

@@ -6,39 +6,74 @@
 
   class NoPopForEmptyStack < RuntimeError
   end
 
   def initialize
-    @elements = []
+    @objects = []
   end
 
   def initialize_copy(orig)
-    @elements = orig.elements
+    @objects = orig.objects
   end
 
-  def elements
-    @elements.dup
+  def objects
+    @objects.dup
   end
 
   def size
-    @elements.size
+    @objects.size
   end
 
+  # doctest: A new Stack should be empty.
+  #   >> stack = Stack.new
+  #   >> stack.empty?
+  #   => true
   def empty?
     size == 0
   end
 
+  # doctest: A new Stack should have no object on top.
+  #   >> stack = Stack.new
+  #   >> begin
+  #   ?>   stack.top
+  #   ?> rescue Test::Unit::AssertionFailedError
+  #   ?>   true
+  #   ?> else
+  #   ?>   false
+  #   ?> end
+  #   => true
   def top
-    @elements.last
+    @objects.last
   end
 
-  def push(element)
-    @elements.push(element)
-    nil
+  # doctest: From a new Stack no object can be popped.
+  #   >> stack = Stack.new
+  #   >> begin
+  #   ?>   stack.pop
+  #   ?> rescue Test::Unit::AssertionFailedError
+  #   ?>   true
+  #   ?> else
+  #   ?>   false
+  #   ?> end
+  #   => true
+  def pop
+    @objects.pop
   end
 
-  def pop
-    raise NoPopForEmptyStack if empty?
-    @elements.pop
+  # doctest: A pushed object should be on the top.
+  #   >> stack = Stack.new
+  #   >> object = Object.new
+  #   >> stack.push(object)
+  #   >> stack.empty?
+  #   => false
+  #   >> stack.top
+  #   => object
+  #   >> stack.pop
+  #   => object
+  #   >> stack.empty?
+  #   => true
+  def push(object)
+    @objects.push(object)
+    nil
   end
 
 end