Method TypeCheck

postgres/parser/sem/tree/type_check.go:1336–1370

TypeCheck implements the Expr interface.

(
	ctx context.Context, semaCtx *SemaContext, desired *types.T,
)

// TypeCheck implements the Expr interface.
func (expr *Tuple) TypeCheck(
	ctx context.Context, semaCtx *SemaContext, desired *types.T,
) (TypedExpr, error) {
	// Ensure the number of labels matches the number of expressions.
	if len(expr.Labels) > 0 && len(expr.Labels) != len(expr.Exprs) {
		return nil, pgerror.Newf(pgcode.Syntax,
			"mismatch in tuple definition: %d expressions, %d labels",
			len(expr.Exprs), len(expr.Labels),
		)
	}

	var labels []string
	contents := make([]*types.T, len(expr.Exprs))
	for i, subExpr := range expr.Exprs {
		desiredElem := types.Any
		if desired.Family() == types.TupleFamily && len(desired.TupleContents()) > i {
			desiredElem = desired.TupleContents()[i]
		}
		typedExpr, err := subExpr.TypeCheck(ctx, semaCtx, desiredElem)
		if err != nil {
			return nil, err
		}
		expr.Exprs[i] = typedExpr
		contents[i] = typedExpr.ResolvedType()
	}
	// Copy the labels if there are any.
	if len(expr.Labels) > 0 {
		labels = make([]string, len(expr.Labels))
		for i := range expr.Labels {
			labels[i] = lex.NormalizeName(expr.Labels[i])
		}
	}
	expr.typ = types.MakeLabeledTuple(contents, labels)
	return expr, nil
}

var errAmbiguousArrayType = pgerror.Newf(pgcode.IndeterminateDatatype, "cannot determine type of empty array. "+
	"Consider annotating with the desired type, for example ARRAY[]:::int[]")