   merge: (n) ->
     if 0 <= n < @_rte.words.length
       w = @getWord(n).trimRight()
-      @deleteWords(n)
-      @insert({startPos: {word: n, pos:0}}, w)
+      @deleteWords n
+      @insert {startPos: {word: n, pos:0}}, w
     else
       throw new Error "Impossible to merge"
 

  # Append new words at the end of the word list
  # @param [String] content the string to append
  push: (content) ->
    console.log '"' + content + '"'
    preSpaces = content.match PreSpacesRegExp
    if preSpaces isnt null
      @_rte.words.push(new Word (preSpaces[0]))
    words = content.match WordRegExp
    console.log '"' + preSpaces + '"'
    console.log words
    if _.isArray(words)
      for w in words
        @_rte.words.push (new Word w)

      else if delta.insert?
        end = position + delta.insert.length
        selection = new Selection position, end, @
        @insert selection, delta.insert
        position = end
      else
        throw new Error "Unknown operation"
