Method parseOptionalTokenAndInt

query/expr/parser.go:198–226

parseOptionalTokenAndInt parses the specified token followed by an int, if it exists.

(t Token)

// parseOptionalTokenAndInt parses the specified token followed
// by an int, if it exists.
func (p *Parser) parseOptionalTokenAndInt(t Token) (int, error) {
	// Check if the token exists.
	if tok, _, _ := p.scanIgnoreWhitespace(); tok != t {
		p.unscan()
		return 0, nil
	}

	// Scan the number.
	tok, pos, lit := p.scanIgnoreWhitespace()
	if tok != NUMBER {
		return 0, newParseError(tokstr(tok, lit), []string{"number"}, pos)
	}

	// Return an error if the number has a fractional part.
	if strings.Contains(lit, ".") {
		msg := fmt.Sprintf("fractional parts not allowed in %s", t.String())
		return 0, &ParseError{Message: msg, Pos: pos}
	}

	// Parse number.
	n, _ := strconv.ParseInt(lit, 10, 64)

	if n < 0 {
		msg := fmt.Sprintf("%s must be >= 0", t.String())
		return 0, &ParseError{Message: msg, Pos: pos}
	}

	return int(n), nil
}

// parseVarRef parses a reference to a measurement or field.
func (p *Parser) parseVarRef() (*VarRef, error) {