// NewUnary returns a unary exprression.
NewUnary returns a unary exprression.
// NewUnary returns a unary exprression .
func NewUnary(typ int, op string, od1 *Expr) (*Expr, error) {
	oprt, e := NewLiteral(typ, op)
	if e != nil {
		return nil, e
	}
	if od1 == nil {
		return nil, fmt.Errorf("The operand of a unary expression is nil")
	}
	return &Expr{
		sexp: append(ExprList{oprt}, od1),
	}, nil
}
func NewUnary ( typ int , op string , od1 * Expr ) ( * Expr , error ) { oprt , e := NewLiteral ( typ , op ) if e != nil { return nil , e } if od1 == nil { return nil , fmt . Errorf ( " " ) } return & Expr { sexp : append ( ExprList { oprt } , od1 ) , } , nil }
NewUnary returns a unary exprression.
NewUnary returns a unary exprression .