From: Ihor Radchenko <yantar92@posteo.net>
To: Jim Porter <jporterbugs@gmail.com>
Cc: 68509@debbugs.gnu.org
Subject: bug#68509: 30.0.50; pcase-dolist matches backquote pattern incorrectly
Date: Mon, 19 Feb 2024 10:05:33 +0000 [thread overview]
Message-ID: <871q98hiqa.fsf@localhost> (raw)
In-Reply-To: <87sf2xjezi.fsf@localhost>
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Ihor Radchenko <yantar92@posteo.net> writes:
> Not sure about pcase-let, but pcase-dolist specifically may be
> simplified not to use pcase-let:
>
> (if (pcase--trivial-upat-p (car spec))
> `(dolist ,spec ,@body)
> (let ((tmpvar (gensym "x")))
> `(dolist (,tmpvar ,@(cdr spec))
> (pcase ,tmpvar (,(car spec) ,@body)))))
See the attached patch.
If the patch is acceptable, we also need to update the manual.
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From f3e1362f7687c731e0ba4e410f005252309ffc3f Mon Sep 17 00:00:00 2001
Message-ID: <f3e1362f7687c731e0ba4e410f005252309ffc3f.1708337064.git.yantar92@posteo.net>
From: Ihor Radchenko <yantar92@posteo.net>
Date: Mon, 19 Feb 2024 13:02:21 +0300
Subject: [PATCH] pcase-let: Skip LIST element that do not match the PATTERN
(bug#68509)
* lisp/emacs-lisp/pcase.el (pcase-dolist): Use `pcase' rather than
`pcase-let*' to match the list elements. Update the docstring,
describing the behavior when list elements to not match the pattern.
The previous undefined behavior is removed.
* test/lisp/emacs-lisp/pcase-tests.el (pcase-tests-pcase-dolist): Add
new test.
---
lisp/emacs-lisp/pcase.el | 13 ++++++-------
test/lisp/emacs-lisp/pcase-tests.el | 12 ++++++++++++
2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/lisp/emacs-lisp/pcase.el b/lisp/emacs-lisp/pcase.el
index ae9bd87997c..8dc11b20a6f 100644
--- a/lisp/emacs-lisp/pcase.el
+++ b/lisp/emacs-lisp/pcase.el
@@ -329,21 +329,20 @@ pcase-let
(defmacro pcase-dolist (spec &rest body)
"Eval BODY once for each set of bindings defined by PATTERN and LIST elements.
PATTERN should be a `pcase' pattern describing the structure of
-LIST elements, and LIST is a list of objects that match PATTERN,
-i.e. have a structure that is compatible with PATTERN.
+LIST elements, and LIST is a list of objects.
For each element of LIST, this macro binds the variables in
PATTERN to the corresponding subfields of the LIST element, and
-then evaluates BODY with these bindings in effect. The
-destructuring bindings of variables in PATTERN to the subfields
-of the elements of LIST is performed as if by `pcase-let'.
+then evaluates BODY with these bindings in effect. When an element does
+not match the pattern, such element is skipped.
+The destructuring bindings of variables in PATTERN to the subfields
+of the elements of LIST is performed as if by `pcase'.
\n(fn (PATTERN LIST) BODY...)"
(declare (indent 1) (debug ((pcase-PAT form) body)))
(if (pcase--trivial-upat-p (car spec))
`(dolist ,spec ,@body)
(let ((tmpvar (gensym "x")))
`(dolist (,tmpvar ,@(cdr spec))
- (pcase-let* ((,(car spec) ,tmpvar))
- ,@body)))))
+ (pcase ,tmpvar (,(car spec) ,@body))))))
;;;###autoload
(defmacro pcase-setq (pat val &rest args)
diff --git a/test/lisp/emacs-lisp/pcase-tests.el b/test/lisp/emacs-lisp/pcase-tests.el
index d062965952a..241729c108a 100644
--- a/test/lisp/emacs-lisp/pcase-tests.el
+++ b/test/lisp/emacs-lisp/pcase-tests.el
@@ -160,4 +160,16 @@ pcase-tests-setq
(should-error (pcase-setq a)
:type '(wrong-number-of-arguments)))
+(ert-deftest pcase-tests-pcase-dolist ()
+ ;; Ignore non-matching elements.
+ (should
+ (equal
+ '(("DONE" . "a"))
+ (let (result)
+ (pcase-dolist (`(,(and (pred stringp) a) .
+ ,(and (pred stringp) b))
+ '(("TODO") ("DONE" . "a")))
+ (push (cons a b) result))
+ (nreverse result)))))
+
;;; pcase-tests.el ends here.
--
2.43.0
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--
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>
next prev parent reply other threads:[~2024-02-19 10:05 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-16 15:07 bug#68509: 30.0.50; pcase-dolist matches backquote pattern incorrectly Ihor Radchenko
2024-01-16 16:52 ` Jim Porter
2024-01-16 18:43 ` Ihor Radchenko
2024-02-19 10:05 ` Ihor Radchenko [this message]
2024-02-19 12:59 ` Eli Zaretskii
2024-02-19 15:53 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-19 18:14 ` Ihor Radchenko
2024-02-20 2:41 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-20 13:40 ` Ihor Radchenko
2024-02-20 14:35 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-20 15:16 ` Ihor Radchenko
2024-02-20 17:51 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-21 11:23 ` Ihor Radchenko
2024-02-21 14:17 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-23 14:05 ` Ihor Radchenko
2024-02-23 14:58 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-24 13:28 ` Ihor Radchenko
2024-02-24 14:57 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-19 15:51 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-02-19 18:16 ` Ihor Radchenko
2024-02-20 2:46 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
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