   OUT: a Node with offset and matchLength
   ###
   subparse: (subsource, options = {}) ->
-    # log subparse: {subsource, options}
 
     subparser = new @class
     {originalMatchLength, parentNode, sourceMap, originalOffset} = options


      out = compactFlatten [
        """
        Parsing error at #{getLineColumnString @_source, @_failureIndex}

        Source:
        ...

      @parentParser.offsetInRootParserSource @offsetInParentParserSource suboffset
    else
      suboffset

  @getter
    failureIndexInParentParser: -> @offsetInParentParserSource @_failureIndex
