compressor.rb in rambling-trie-0.5.2

- old
+ new

@@ -3,17 +3,17 @@
     # Provides the compressing behavior for the Trie data structure.
     module Compressor
       # Flag for compressed tries.
       # @return [Boolean] `true` for compressed tries, `false` otherwise.
       def compressed?
-        parent and parent.compressed?
+        parent && parent.compressed?
       end
 
       # Compress the current node using redundant node elimination.
       # @return [Root, Node] the compressed node.
       def compress_tree!
-        if children.size == 1 and not terminal? and letter
+        if children.size == 1 && !terminal? && letter
           merge_with! children.values.first
           compress_tree!
         end
 
         children.values.each &:compress_tree!
@@ -22,26 +22,23 @@
       end
 
       private
 
       def merge_with!(child)
-        new_letter = (letter.to_s << child.letter.to_s).to_sym
+        delete_old_key_on_parent!
+        redefine_self! child
 
-        rehash_on_parent! letter, new_letter
-        redefine_self! new_letter, child
-
-        children.values.each { |node| node.parent = self }
+        children.each { |_, node| node.parent = self }
       end
 
-      def rehash_on_parent!(old_letter, new_letter)
+      def delete_old_key_on_parent!
         return if parent.nil?
 
-        parent.delete old_letter
-        parent[new_letter] = self
+        parent.delete letter
       end
 
-      def redefine_self!(new_letter, merged_node)
-        self.letter = new_letter
+      def redefine_self!(merged_node)
+        self.letter = letter.to_s << merged_node.letter.to_s
         self.children = merged_node.children
         self.terminal = merged_node.terminal?
       end
     end
   end