code: func split(data []byte) [][]byte {
  	chunks := [][]byte{}
  
  	start := 0
  	dirDepth := 0
  	for i, b := range data {
  		switch b {
  		case dirStartMark:
  			dirDepth++
  		case dirEndMark:
  			dirDepth--
  		case dirElementSep:
  			if dirDepth == 0 {
  				chunks = append(chunks, data[start:i+1])
  				start = i + 1
  			}
  		}
  	}
  	chunks = append(chunks, data[start:])
  
  	return chunks
  }
docs: // returns the description of the elements of a dir.  It is just looking
  // for spaces if they are not part of inner dirs.