code: func NewParser(r io.Reader, err func(Error) bool) Parser {
  	return &parser{_lexer: NewLexer(r), _error: err}
  }
docs: // NewParser returns a new Parser instance for the given stream r.
  // If err is not nil, it will be called for every error encountered during
  // parsing. Parsing will terminate at the end of the stream, or if err
  // returns false.