polyadic_expression.rb in rley-0.6.01

- old
+ new
@@ -1,64 +1,60 @@
 # File: polyadic_expression.rb
 
-require_relative "compound_expression"	# Access the superclass
+require_relative 'compound_expression' # Access the superclass
 
 module Regex # This module is used as a namespace
+  # Abstract class. An element that is part of a regular expression &
+  # that has its own child sub-expressions.
+  class PolyadicExpression < CompoundExpression
+    # The aggregation of child elements
+    attr_reader(:children)
 
-# Abstract class. An element that is part of a regular expression &  
-# that has its own child sub-expressions.
-class PolyadicExpression < CompoundExpression
-	# The aggregation of child elements
-	attr_reader(:children)
-	
-	# Constructor.
-	def initialize(theChildren)
-		super()	
-		@children = theChildren
-	end
-	
-public
-	# Append the given child to the list of children.
-	# TODO: assess whether to defer to a subclass NAryExpression
-	def <<(aChild)
-		@children << aChild
-		
-		return self
-	end
-	
-	# Build a depth-first in-order children visitor.
-	# The visitor is implemented as an Enumerator.
-	def df_visitor()
-		root = children	# The visit will start from the children of this object
-		
-		visitor = Enumerator.new do |result|	# result is a Yielder
-			# Initialization part: will run once
-			visit_stack = [ root ]	# The LIFO queue of nodes to visit
-			
-			begin	# Traversal part (as a loop)
-				top = visit_stack.pop()
-				if top.kind_of?(Array)
-					if top.empty?
-						next
-					else
-						currChild = top.pop()
-						visit_stack.push top					
-					end
-				else
-					currChild = top
-				end
-				
-				result << currChild		# Return the visited child
-				
-				unless currChild.atomic?
-					children_to_enqueue = currChild.children.reverse()	# in-order traversal implies LIFO queue
-					visit_stack.push(children_to_enqueue)
-				end			
-			end until visit_stack.empty?
-		end
-	end
+    # Constructor.
+    def initialize(theChildren)
+      super()
+      @children = theChildren
+    end
 
-end # class
+    # Append the given child to the list of children.
+    # TODO: assess whether to defer to a subclass NAryExpression
+    def <<(aChild)
+      @children << aChild
 
+      return self
+    end
+
+    # Build a depth-first in-order children visitor.
+    # The visitor is implemented as an Enumerator.
+    def df_visitor()
+      root = children # The visit will start from the children of this object
+
+      visitor = Enumerator.new do |result| # result is a Yielder
+        # Initialization part: will run once
+        visit_stack = [root] # The LIFO queue of nodes to visit
+
+        begin # Traversal part (as a loop)
+          top = visit_stack.pop
+          if top.kind_of?(Array)
+            next if top.empty?
+            currChild = top.pop
+            visit_stack.push top
+          else
+            currChild = top
+          end
+
+          result << currChild # Return the visited child
+
+          unless currChild.atomic?
+            # in-order traversal implies LIFO queue
+            children_to_enqueue = currChild.children.reverse
+            visit_stack.push(children_to_enqueue)
+          end
+        end until visit_stack.empty?
+      end
+      
+      return visitor
+    end
+  end # class
 end # module
 
-# End of file
\ No newline at end of file
+# End of file