Method parseSegmentedIdents

query/expr/parser.go:137–175

parseSegmentedIdents parses a segmented identifiers. e.g., "db"."rp".measurement or "db"..measurement

()

// parseSegmentedIdents parses a segmented identifiers.
// e.g.,  "db"."rp".measurement  or  "db"..measurement
func (p *Parser) parseSegmentedIdents() ([]string, error) {
	ident, err := p.parseIdent()
	if err != nil {
		return nil, err
	}
	idents := []string{ident}

	// Parse remaining (optional) identifiers.
	for {
		if tok, _, _ := p.scan(); tok != DOT {
			// No more segments so we're done.
			p.unscan()
			break
		}

		if ch := p.peekRune(); ch == '/' {
			// Next segment is a regex so we're done.
			break
		} else if ch == '.' {
			// Add an empty identifier.
			idents = append(idents, "")
			continue
		}

		// Parse the next identifier.
		if ident, err = p.parseIdent(); err != nil {
			return nil, err
		}

		idents = append(idents, ident)
	}

	if len(idents) > 3 {
		msg := fmt.Sprintf("too many segments in %s", QuoteIdent(idents...))
		return nil, &ParseError{Message: msg}
	}

	return idents, nil
}

// parserString parses a string.
func (p *Parser) parseString() (string, error) {