code: func POSTagShortcut(l Lexeme) (POSTag, bool) {
  	switch l.LexemeType {
  	case Number:
  		return CD, true
  	case Punctuation:
  		switch l.Value {
  		case ",":
  			return COMMA, true
  		case ".":
  			return FULLSTOP, true
  		case "``":
  			return OPENQUOTE, true
  		case "''":
  			return CLOSEQUOTE, true
  		case ":":
  			return COLON, true
  		case "#":
  			return HASHSIGN, true
  		case "(":
  			return LEFTBRACE, true
  		case ")":
  			return RIGHTBRACE, true
  		default:
  			return X, false
  		}
  	case Symbol:
  		return SYM, true
  	case URI:
  		return ADD, true
  	case Date:
  		return CD, true
  	case Time:
  		return CD, true
  	case EOF:
  		return X, true
  	}
  	return X, false
  }
docs: // POSTagShortcut is a shortcut function to help the POSTagger shortcircuit some decisions about what the tag is