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

      @parentParser.offsetInRootParserSource @offsetInParentParserSource suboffset
    else
      suboffset
    # log offsetInRootParserSourceA: {suboffset}
    # @_parentParserRootOffset ?= if @parentParser
    #   @parentParser?.offsetInRootParserSource(0)
    # else 0
    # log offsetInRootParserSourceB: {suboffset, @_parentParserRootOffset, @source, offsetInParentParserSource: @offsetInParentParserSource suboffset}
    # @_parentParserRootOffset + @offsetInParentParserSource suboffset

  @getter
    failureIndexInParentParser: -> @offsetInParentParserSource @_failureIndex


      out = compactFlatten [
        """
        Parsing error at #{@options.sourceFile || ''}:#{getLineColumnString @_source, @_failureIndex}

        Source:
        ...
