compressor.rb in rambling-trie-0.5.0

- old
+ new

@@ -6,14 +6,14 @@
       # @return [Boolean] `true` for compressed tries, `false` otherwise.
       def compressed?
         @parent.nil? ? false : @parent.compressed?
       end
 
-      # Compressed the current node using redundant node elimination.
+      # 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 not @letter.nil?
+        if @children.size == 1 and not terminal? and @letter
           merge_with! @children.values.first
           compress_tree!
         end
 
         @children.values.each &:compress_tree!
@@ -22,10 +22,10 @@
       end
 
       private
 
       def merge_with!(child)
-        new_letter = (@letter.to_s + child.letter.to_s).to_sym
+        new_letter = (@letter.to_s << child.letter.to_s).to_sym
 
         rehash_on_parent! @letter, new_letter
         redefine_self! new_letter, child
 
         @children.values.each { |node| node.parent = self }