bug#50719: Cannot add a no-applicable-method implementation for a generic with no method
Vivien Kraus via "Bug reports for GUILE, GNU's Ubiquitous Extension Language" <[email protected]>
| Newsgroups | gmane.lisp.guile.bugs |
|---|---|
| Message-ID | <[email protected]> |
Dear guile,
The following program should just return 'foo, but it enters an
infinite loop:
(use-modules (oop goops))
(define-class <my-generic> (<generic>))
(define-method (no-method (generic <my-generic>) args)
'foo)
(define-method (no-applicable-method (generic <my-generic>) args)
'foo)
(define hello
(make <my-generic>
#:name 'hello))
(hello)
I don’t know GOOPS enough to understand what happens, but when I
slightly change the last line:
(use-modules (oop goops))
(define-class <my-generic> (<generic>))
(define-method (no-method (generic <my-generic>) args)
'foo)
(define-method (no-applicable-method (generic <my-generic>) args)
'foo)
(define hello
(make <my-generic>
#:name 'hello))
(apply-generic hello '())
Now it returns 'foo, as expected. So my guess is that the infinite
loops happens during the memoization phase. More specifically, the no-
applicable-method is called over and over again.
Please find a failing test case attached.
Best regards,
Vivien
0001-goops-cannot-override-no-applicable-method-for-a-gen.patch
(text/x-patch, 1.5 KB)
From 435d4d7569a25dda05489c3eda3086e0dbf531af Mon Sep 17 00:00:00 2001 From: Vivien Kraus <[email protected]> Date: Tue, 21 Sep 2021 11:40:43 +0200 Subject: [PATCH] goops: cannot override no-applicable-method for a generic that has no methods --- test-suite/tests/goops.test | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/test-suite/tests/goops.test b/test-suite/tests/goops.test index b06ba98b2..626eeaacd 100644 --- a/test-suite/tests/goops.test +++ b/test-suite/tests/goops.test @@ -761,3 +761,22 @@ #:metaclass <redefinable-meta>))) (pass-if-equal 123 (get-the-bar (make <foo>))) (pass-if-equal 123 (get-the-bar (make <redefinable-foo>)))))) + +(with-test-prefix "Can override no-applicable-method in a generic without methods" + (let ((patience-no-method 10) + (patience-no-applicable-method 10)) + (define-class <my-generic> (<generic>)) + (define-method (no-method (generic <my-generic>) args) + (when (= patience-no-method 0) + (error "Infinite loop detected in no-method")) + (set! patience-no-method (- patience-no-method 1)) + 'foo) + (define-method (no-applicable-method (generic <my-generic>) args) + (when (= patience-no-applicable-method 0) + (error "Infinite loop detected in no-applicable-method")) + (set! patience-no-applicable-method (- patience-no-applicable-method 1)) + 'foo) + (define hello + (make <my-generic> + #:name 'hello)) + (pass-if-equal (hello) 'foo))) -- 2.33.0