bug#70209: 30.0.50; describe key + lambda too poetic

bug#70209: 30.0.50; describe key + lambda too poetic

[No Wayman]

GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 
3.24.41, cairo version 1.18.0) of 2024-04-02  

emacs -Q --batch \
--eval '(global-set-key (kbd "c") (lambda () (interactive) t))' \
--eval '(describe-key "c")' \
--eval '(with-current-buffer "*Help*" (print 
  (buffer-substring-no-properties (point-min) (point-max))))'

Outputs the following poetry:

"c runs the command #<closure 0FE> (found in global-map), which is 
.

It is bound to c.

(anonymous)
"

"which is..."?
What is describe-key trying to tell us?
Is it respecting the function's wish to remain anonymous?
Is it commentary on the limits of descriptive language?
I can only respond with the output of M-x describe-feelings:

"It is bound to c, yet I see a bind:
Though closure mentioned, none I've yet to find."
~ Anonymous

bug#70209: 30.0.50; describe key + lambda too poetic

[No Wayman]

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See attached patch, which is.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-Include-lambda-type-in-describe-key-output.patch --]
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From 65f0f2fa251a7b18c15698460c499394b931d09d Mon Sep 17 00:00:00 2001
From: Nicholas Vollmer <iarchivedmywholelife@gmail.com>
Date: Thu, 4 Apr 2024 23:54:42 -0400
Subject: [PATCH] Include lambda type in describe-key output

* lisp/help-fns.el (help-fns-function-description-header):
Add case to describe lambda forms (Bug#70209).
---
 lisp/help-fns.el | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index a291893e9a2..3a5984d5b84 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -1102,6 +1102,8 @@ help-fns-function-description-header
 				elts nil))
 		      (setq elts (cdr-safe elts)))
 		    (concat beg (if is-full "keymap" "sparse keymap"))))
+                 ((eq (car-safe def) 'lambda)
+                  (concat beg "anonymous Lisp function"))
 		 (t ""))))
     (with-current-buffer standard-output
       (insert description))
-- 
2.44.0

bug#70209: 30.0.50; describe key + lambda too poetic

[Eli Zaretskii]

> From: No Wayman <iarchivedmywholelife@gmail.com>
> Date: Fri, 05 Apr 2024 01:07:39 -0400
> 
> See attached patch, which is.

Thanks.  Stefan, any comments?

bug#70209: 30.0.50; describe key + lambda too poetic

[Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Thank you for your enjoyable bug report and the suggested patch.

> @@ -1102,6 +1102,8 @@ help-fns-function-description-header
>  				elts nil))
>  		      (setq elts (cdr-safe elts)))
>  		    (concat beg (if is-full "keymap" "sparse keymap"))))
> +                 ((eq (car-safe def) 'lambda)
> +                  (concat beg "anonymous Lisp function"))
>  		 (t ""))))
>      (with-current-buffer standard-output
>        (insert description))

Actually, I think this won't help because in my test the `car` of `def`
is `closure` rather than `lambda`.

I installed the patch below instead.


        Stefan


diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index a291893e9a2..27011575333 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -1086,13 +1086,6 @@ help-fns-function-description-header
 		      ;; need to check macros before functions.
 		      (macrop function))
 		  (concat beg "Lisp macro"))
-		 ((atom def)
-		  (let ((type (or (oclosure-type def) (cl-type-of def))))
-		    (concat beg (format "%s"
-		                        (make-text-button
-		                         (symbol-name type) nil
-		                         'type 'help-type
-		                         'help-args (list type))))))
 		 ((keymapp def)
 		  (let ((is-full nil)
 			(elts (cdr-safe def)))
@@ -1102,7 +1095,16 @@ help-fns-function-description-header
 				elts nil))
 		      (setq elts (cdr-safe elts)))
 		    (concat beg (if is-full "keymap" "sparse keymap"))))
-		 (t ""))))
+		 (t
+		  (let ((type
+		         (if (and (consp def) (symbolp (car def)))
+		             (car def)
+		           (or (oclosure-type def) (cl-type-of def)))))
+		    (concat beg (format "%s"
+		                        (make-text-button
+		                         (symbol-name type) nil
+		                         'type 'help-type
+		                         'help-args (list type)))))))))
     (with-current-buffer standard-output
       (insert description))
 

bug#70209: 30.0.50; describe key + lambda too poetic

[No Wayman]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Thank you for your enjoyable bug report and the suggested patch.

:)

> Actually, I think this won't help because in my test the `car` 
> of `def`
> is `closure` rather than `lambda`.
>
> I installed the patch below instead.
> diff --git a/lisp/help-fns.el b/lisp/help-fns.el
> index a291893e9a2..27011575333 100644

With patch applied, thy *scratch* prepared to itch which I bemoan,
*Help* link replied, its ink ensnared, with "lambda, type 
 Unknown."[1]
Apostrophized: "Be tossed, repaired, my user-error thrown!"
With paren pride, I then declared a test which I have shown.[2]
Test now revised as thou compared. Composure hath no throne
when teary-eyed, in fear I blared, "My closure! Type Unknown?"


[1]:
emacs -Q --batch \
--eval '(global-set-key (kbd "c") `(lambda () (interactive) t)))' 
  \
--eval '(describe-key "c")' \
--eval '(with-current-buffer "*Help*"
           (forward-button 2)
           (push-button)
           (print (buffer-substring-no-properties (point-min) 
           (point-max))))'

Unknown type lambda

[2]:
emacs -Q --batch \
--eval '(global-set-key (kbd "c") (lambda () (interactive) t)))' \
--eval '(describe-key "c")' \
--eval '(with-current-buffer "*Help*"
           (forward-button 2)
           (push-button)
           (print (buffer-substring-no-properties (point-min) 
           (point-max))))'

Unknown type closure

bug#70209: 30.0.50; describe key + lambda too poetic

[Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors]

> [1]:
> emacs -Q --batch \
> --eval '(global-set-key (kbd "c") `(lambda () (interactive) t)))'   \
> --eval '(describe-key "c")' \
> --eval '(with-current-buffer "*Help*"
>           (forward-button 2)
>           (push-button)
>           (print (buffer-substring-no-properties (point-min)
>            (point-max))))'
>
> Unknown type lambda

That's mild punishment for quoting a lambda.

> [2]:
> emacs -Q --batch \
> --eval '(global-set-key (kbd "c") (lambda () (interactive) t)))' \
> --eval '(describe-key "c")' \
> --eval '(with-current-buffer "*Help*"
>           (forward-button 2)
>           (push-button)
>           (print (buffer-substring-no-properties (point-min)
>            (point-max))))'
>
> Unknown type closure

OK, OK, I relent, it shouldn't be button.
Should be fixed now on `master`, thanks to the handy patch below.


        Stefan


diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index 27011575333..cfe27077055 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -1096,15 +1096,15 @@ help-fns-function-description-header
 		      (setq elts (cdr-safe elts)))
 		    (concat beg (if is-full "keymap" "sparse keymap"))))
 		 (t
-		  (let ((type
-		         (if (and (consp def) (symbolp (car def)))
-		             (car def)
-		           (or (oclosure-type def) (cl-type-of def)))))
-		    (concat beg (format "%s"
-		                        (make-text-button
-		                         (symbol-name type) nil
-		                         'type 'help-type
-		                         'help-args (list type)))))))))
+		  (concat beg (format "%s"
+		                      (if (and (consp def) (symbolp (car def)))
+		                          (car def)
+		                        (let ((type (or (oclosure-type def)
+		                                        (cl-type-of def))))
+		                          (make-text-button
+		                           (symbol-name type) nil
+		                           'type 'help-type
+		                           'help-args (list type))))))))))
     (with-current-buffer standard-output
       (insert description))
 

bug#70209: 30.0.50; describe key + lambda too poetic

[No Wayman]

Stefan Monnier <monnier@iro.umontreal.ca> writes: 
 
> That's mild punishment for quoting a lambda.

Alas, that form doth quote itself!
A parcel pulled from off the shelf
unfurls a worm somewhat shoddy 
when passed betwixt macro's body.
 
> OK, OK, I relent, it shouldn't be button.  Should be fixed now 
> on `master`, thanks to the handy patch below.

And though the worm may bore the fruit
thou treat it warm! No frore repute!
Soil tilled from core to clover.
Thy patch doth bring a type of closure.

;; poem.el ends here

Thanks, Stefan

bug#70209: 30.0.50; describe key + lambda too poetic

[Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors]

> Thanks, Stefan

My pleasure, closing,


        Stefan