Method TypeCheck

postgres/parser/sem/tree/type_check.go:1053–1070

TypeCheck implements the Expr interface.

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

// TypeCheck implements the Expr interface.
func (expr *IfExpr) TypeCheck(
	ctx context.Context, semaCtx *SemaContext, desired *types.T,
) (TypedExpr, error) {
	typedCond, err := typeCheckAndRequireBoolean(ctx, semaCtx, expr.Cond, "IF condition")
	if err != nil {
		return nil, err
	}

	typedSubExprs, retType, err := TypeCheckSameTypedExprs(ctx, semaCtx, desired, expr.True, expr.Else)
	if err != nil {
		return nil, decorateTypeCheckError(err, "incompatible IF expressions")
	}

	expr.Cond = typedCond
	expr.True, expr.Else = typedSubExprs[0], typedSubExprs[1]
	expr.typ = retType
	return expr, nil
}

// TypeCheck implements the Expr interface.
func (expr *IsOfTypeExpr) TypeCheck(