Method parseColumnCastExpr

parser/parser_column.go:484–531

(pos Pos)

}

func (p *Parser) parseColumnCastExpr(pos Pos) (Expr, error) {
	if err := p.expectKeyword(KeywordCast); err != nil {
		return nil, err
	}

	if err := p.expectTokenKind(TokenKindLParen); err != nil {
		return nil, err
	}

	columnExpr, err := p.parseColumnExpr(p.Pos())
	if err != nil {
		return nil, err
	}

	var separator string
	asPos := p.Pos()
	switch {
	// CAST(x, T) and CAST(x AS T) are equivalent
	case p.matchKeyword(KeywordAs), p.matchTokenKind(","):
		separator = p.last().String
		_ = p.lexer.consumeToken()
	default:
		return nil, fmt.Errorf("expected AS or , but got %s", p.lastTokenKind())
	}

	var asColumnType Expr
	// CAST(1 AS 'Float') or CAST(1 AS Float) are equivalent
	if p.matchTokenKind(TokenKindString) {
		asColumnType, err = p.parseString(p.Pos())
	} else {
		asColumnType, err = p.parseColumnType(p.Pos())
	}
	if err != nil {
		return nil, err
	}

	if err := p.expectTokenKind(TokenKindRParen); err != nil {
		return nil, err
	}

	return &CastExpr{
		CastPos:   pos,
		AsPos:     asPos,
		Separator: separator,
		Expr:      columnExpr,
		AsType:    asColumnType,
	}, nil
}

func (p *Parser) parseColumnExprListWithLParen(pos Pos) (*ColumnExprList, error) {
	return p.parseColumnExprListWithTerm(TokenKindRParen, pos)