bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Protesilaos Stavrou]

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Dear maintainers,

I was wondering whether we could make the sorting of candidates in the
Completions' buffer subject to a user option.

See the attached patch for a possible implementation.  I have kept it
backward-compatible by making string-lessp the default sort function.

All the best,
Protesilaos

-- 
Protesilaos Stavrou
https://protesilaos.com

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From e53bd2b2383f3dfa367f2af8d4ed43c6c42dd002 Mon Sep 17 00:00:00 2001
Message-Id: <e53bd2b2383f3dfa367f2af8d4ed43c6c42dd002.1642595067.git.info@protesilaos.com>
From: Protesilaos Stavrou <info@protesilaos.com>
Date: Wed, 19 Jan 2022 14:20:19 +0200
Subject: [PATCH] Make Completions sorting a user option

* etc/NEWS: Document the new user option.
* lisp/minibuffer.el (completions-sort): Add new user option.
(minibuffer-completion-help): Implement it for the Completions buffer.
---
 etc/NEWS           |  6 ++++++
 lisp/minibuffer.el | 19 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/etc/NEWS b/etc/NEWS
index 47dbfba9c0..c2d442833c 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -418,6 +418,12 @@ When non-nil, the commands 'next-completion' and 'previous-completion'
 automatically wrap around on reaching the beginning or the end of
 the *Completions* buffer.
 
+*** New user option 'completions-sort'.
+Controls the sorting of the completion candidates in the *Completions*
+buffer.  Available styles are no sorting, alphabetical, lexicographic
+(the default), or a custom sort function.  The function takes and
+returns a list of completion candidate strings.
+
 ** Isearch and Replace
 
 +++
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index ab760a42d1..d64b0cbd24 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1169,6 +1169,20 @@ (defcustom completion-cycle-threshold nil
   :version "24.1"
   :type completion--cycling-threshold-type)
 
+(defcustom completions-sort 'lexicographic
+  "Sort candidates in the *Completions* buffer.
+
+The value can be nil to disable sorting altogether,
+`alphabetical' for alphabetical sorting, `lexicographic' for
+lexicographic sorting, or a custom sorting function.  The sorting
+function takes and returns a list of completion candidate
+strings."
+  :type '(choice (const :tag "No sorting" nil)
+                 (const :tag "Alphabetical sorting" alphabetical)
+                 (const :tag "Lexicographic sorting" lexicographic)
+                 function :tag "Custom function")
+  :version "29.1")
+
 (defcustom completions-group nil
   "Enable grouping of completion candidates in the *Completions* buffer.
 See also `completions-group-format' and `completions-group-sort'."
@@ -2264,7 +2278,10 @@ (defun minibuffer-completion-help (&optional start end)
                       ;; same, but not always.
                       (setq completions (if sort-fun
                                             (funcall sort-fun completions)
-                                          (sort completions 'string-lessp)))
+                                          (pcase completions-sort
+                                            ('alphabetical (sort completions #'string-version-lessp))
+                                            ('lexicographic (sort completions #'string-lessp))
+                                            (_ completions))))
 
                       ;; After sorting, group the candidates using the
                       ;; `group-function'.
-- 
2.34.1

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Eli Zaretskii]

> From: Protesilaos Stavrou <info@protesilaos.com>
> Date: Wed, 19 Jan 2022 14:26:47 +0200
> 
> +(defcustom completions-sort 'lexicographic
> +  "Sort candidates in the *Completions* buffer.
> +
> +The value can be nil to disable sorting altogether,
> +`alphabetical' for alphabetical sorting, `lexicographic' for
> +lexicographic sorting

Here you expect everyone to understand the subtle difference between
these two sorting orders.  I don't think this expectation is
reasonable.

> +                                            ('alphabetical (sort completions #'string-version-lessp))

Doesn't string-version-lessp do stuff that is only appropriate with
version numbers like 1.2.3beta?

Thanks.

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Protesilaos Stavrou]

On 2022-01-19, 14:56 +0200, Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Protesilaos Stavrou <info@protesilaos.com>
>> Date: Wed, 19 Jan 2022 14:26:47 +0200
>> 
>> +(defcustom completions-sort 'lexicographic
>> +  "Sort candidates in the *Completions* buffer.
>> +
>> +The value can be nil to disable sorting altogether,
>> +`alphabetical' for alphabetical sorting, `lexicographic' for
>> +lexicographic sorting
>
> Here you expect everyone to understand the subtle difference between
> these two sorting orders.  I don't think this expectation is
> reasonable.

Perhaps it is better to reference string-lessp and string-version-lessp
directly?

>> +                                            ('alphabetical (sort completions #'string-version-lessp))
>
> Doesn't string-version-lessp do stuff that is only appropriate with
> version numbers like 1.2.3beta?

It also helps when the string starts with a number:

    (sort '("1 test" "21 test" "11 test" "2 test") #'string-lessp)
    ;; => ("1 test" "11 test" "2 test" "21 test")

    (sort '("1 test" "21 test" "11 test" "2 test") #'string-version-lessp)
    ;; => ("1 test" "2 test" "11 test" "21 test")


-- 
Protesilaos Stavrou
https://protesilaos.com

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Eli Zaretskii]

> From: Protesilaos Stavrou <info@protesilaos.com>
> Cc: 53362@debbugs.gnu.org
> Date: Wed, 19 Jan 2022 15:17:13 +0200
> 
> >> +(defcustom completions-sort 'lexicographic
> >> +  "Sort candidates in the *Completions* buffer.
> >> +
> >> +The value can be nil to disable sorting altogether,
> >> +`alphabetical' for alphabetical sorting, `lexicographic' for
> >> +lexicographic sorting
> >
> > Here you expect everyone to understand the subtle difference between
> > these two sorting orders.  I don't think this expectation is
> > reasonable.
> 
> Perhaps it is better to reference string-lessp and string-version-lessp
> directly?

That'd be a step backward, IMO.

> > Doesn't string-version-lessp do stuff that is only appropriate with
> > version numbers like 1.2.3beta?
> 
> It also helps when the string starts with a number:
> 
>     (sort '("1 test" "21 test" "11 test" "2 test") #'string-lessp)
>     ;; => ("1 test" "11 test" "2 test" "21 test")

Yes, and how does that match the "alphabetical order" description?

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Protesilaos Stavrou]

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On 2022-01-19, 15:27 +0200, Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Protesilaos Stavrou <info@protesilaos.com>
>> Cc: 53362@debbugs.gnu.org
>> Date: Wed, 19 Jan 2022 15:17:13 +0200
>> 
>> >> +(defcustom completions-sort 'lexicographic
>> >> +  "Sort candidates in the *Completions* buffer.
>> >> +
>> >> +The value can be nil to disable sorting altogether,
>> >> +`alphabetical' for alphabetical sorting, `lexicographic' for
>> >> +lexicographic sorting
>> >
>> > Here you expect everyone to understand the subtle difference between
>> > these two sorting orders.  I don't think this expectation is
>> > reasonable.
>> 
>> Perhaps it is better to reference string-lessp and string-version-lessp
>> directly?
>
> That'd be a step backward, IMO.
>
>> > Doesn't string-version-lessp do stuff that is only appropriate with
>> > version numbers like 1.2.3beta?
>> 
>> It also helps when the string starts with a number:
>> 
>>     (sort '("1 test" "21 test" "11 test" "2 test") #'string-lessp)
>>     ;; => ("1 test" "11 test" "2 test" "21 test")
>
> Yes, and how does that match the "alphabetical order" description?

In the revised patch (see attached), I follow the example of
completions-group-sort.

-- 
Protesilaos Stavrou
https://protesilaos.com

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From 3e9e0c2310afdcc921cda2a6d431d7fcbe1eb01a Mon Sep 17 00:00:00 2001
Message-Id: <3e9e0c2310afdcc921cda2a6d431d7fcbe1eb01a.1642601249.git.info@protesilaos.com>
From: Protesilaos Stavrou <info@protesilaos.com>
Date: Wed, 19 Jan 2022 14:20:19 +0200
Subject: [PATCH] Make Completions sorting a user option

* etc/NEWS: Document the new user option.
* lisp/minibuffer.el (completions-sort): Add new user option.
(minibuffer-completion-help): Implement it for the Completions buffer.
---
 etc/NEWS           |  6 ++++++
 lisp/minibuffer.el | 16 +++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/etc/NEWS b/etc/NEWS
index 47dbfba9c0..8f68336d30 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -418,6 +418,12 @@ When non-nil, the commands 'next-completion' and 'previous-completion'
 automatically wrap around on reaching the beginning or the end of
 the *Completions* buffer.
 
+*** New user option 'completions-sort'.
+Controls the sorting of the completion candidates in the *Completions*
+buffer.  Available styles are no sorting, alphabetical (the default),
+or a custom sort function (e.g. 'string-version-lessp').  The function
+takes and returns a list of completion candidate strings.
+
 ** Isearch and Replace
 
 +++
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index ab760a42d1..7b7e734b72 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1169,6 +1169,18 @@ (defcustom completion-cycle-threshold nil
   :version "24.1"
   :type completion--cycling-threshold-type)
 
+(defcustom completions-sort 'alphabetical
+  "Sort candidates in the *Completions* buffer.
+
+The value can be nil to disable sorting, `alphabetical' for
+alphabetical sorting or a custom sorting function.  The sorting
+function takes and returns a list of completion candidate
+strings."
+  :type '(choice (const :tag "No sorting" nil)
+                 (const :tag "Alphabetical sorting" alphabetical)
+                 function :tag "Custom function")
+  :version "29.1")
+
 (defcustom completions-group nil
   "Enable grouping of completion candidates in the *Completions* buffer.
 See also `completions-group-format' and `completions-group-sort'."
@@ -2264,7 +2276,9 @@ (defun minibuffer-completion-help (&optional start end)
                       ;; same, but not always.
                       (setq completions (if sort-fun
                                             (funcall sort-fun completions)
-                                          (sort completions 'string-lessp)))
+                                          (pcase completions-sort
+                                            ('alphabetical (sort completions #'string-lessp))
+                                            (_ completions))))
 
                       ;; After sorting, group the candidates using the
                       ;; `group-function'.
-- 
2.34.1

bug#53362: [External] : bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Drew Adams]

See library sortie.el.

* Description: https://www.emacswiki.org/emacs/Sortie

* Code: https://www.emacswiki.org/emacs/download/sortie.el

You can define sort orders and choose among them on the fly.

Different sort orders are appropriate for different operations, different sets of completion candidates, and different use cases/contexts and users.

A user option to choose a preferred sort order is at best appropriate for an overall _default_ sort order.

It could also be a place to hold a set of sort orders, including orders defined by a user.  But on its own, it can't deal with the need to be able to change sort orders anytime.

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Protesilaos Stavrou]

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On 2022-01-19, 16:09 +0200, Protesilaos Stavrou <info@protesilaos.com> wrote:

> In the revised patch (see attached), I follow the example of
> completions-group-sort.

I sent a faulty patch.  Sorry!  Attached is the one that should work as intended.

-- 
Protesilaos Stavrou
https://protesilaos.com

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From 401b48c9b14f71dfa0f44e426fbbfe8fa48fd0f8 Mon Sep 17 00:00:00 2001
Message-Id: <401b48c9b14f71dfa0f44e426fbbfe8fa48fd0f8.1642612531.git.info@protesilaos.com>
From: Protesilaos Stavrou <info@protesilaos.com>
Date: Wed, 19 Jan 2022 14:20:19 +0200
Subject: [PATCH] Make Completions sorting a user option

* etc/NEWS: Document the new user option.
* lisp/minibuffer.el (completions-sort): Add new user option.
(minibuffer-completion-help): Implement it for the Completions buffer.
---
 etc/NEWS           |  6 ++++++
 lisp/minibuffer.el | 17 ++++++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/etc/NEWS b/etc/NEWS
index 47dbfba9c0..8f68336d30 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -418,6 +418,12 @@ When non-nil, the commands 'next-completion' and 'previous-completion'
 automatically wrap around on reaching the beginning or the end of
 the *Completions* buffer.
 
+*** New user option 'completions-sort'.
+Controls the sorting of the completion candidates in the *Completions*
+buffer.  Available styles are no sorting, alphabetical (the default),
+or a custom sort function (e.g. 'string-version-lessp').  The function
+takes and returns a list of completion candidate strings.
+
 ** Isearch and Replace
 
 +++
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index ab760a42d1..f332ef3793 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1169,6 +1169,18 @@ (defcustom completion-cycle-threshold nil
   :version "24.1"
   :type completion--cycling-threshold-type)
 
+(defcustom completions-sort 'alphabetical
+  "Sort candidates in the *Completions* buffer.
+
+The value can be nil to disable sorting, `alphabetical' for
+alphabetical sorting or a custom sorting function.  The sorting
+function takes and returns a list of completion candidate
+strings."
+  :type '(choice (const :tag "No sorting" nil)
+                 (const :tag "Alphabetical sorting" alphabetical)
+                 function :tag "Custom function")
+  :version "29.1")
+
 (defcustom completions-group nil
   "Enable grouping of completion candidates in the *Completions* buffer.
 See also `completions-group-format' and `completions-group-sort'."
@@ -2264,7 +2276,10 @@ (defun minibuffer-completion-help (&optional start end)
                       ;; same, but not always.
                       (setq completions (if sort-fun
                                             (funcall sort-fun completions)
-                                          (sort completions 'string-lessp)))
+                                          (pcase completions-sort
+                                            ('nil completions)
+                                            ('alphabetical (sort completions #'string-lessp))
+                                            (_ (sort completions completions-sort)))))
 
                       ;; After sorting, group the candidates using the
                       ;; `group-function'.
-- 
2.34.1

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Protesilaos Stavrou]

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On 2022-01-19, 19:16 +0200, Protesilaos Stavrou <info@protesilaos.com> wrote:

> On 2022-01-19, 16:09 +0200, Protesilaos Stavrou <info@protesilaos.com> wrote:
>
>> In the revised patch (see attached), I follow the example of
>> completions-group-sort.
>
> I sent a faulty patch.  Sorry!  Attached is the one that should work as intended.

This is awkward: I sent the wrong file twice.

If you are still reading this, I attach the definitive patch.

-- 
Protesilaos Stavrou
https://protesilaos.com

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From c5538d31855ba7184ffbd51230d17b81e5a083fe Mon Sep 17 00:00:00 2001
Message-Id: <c5538d31855ba7184ffbd51230d17b81e5a083fe.1642656616.git.info@protesilaos.com>
From: Protesilaos Stavrou <info@protesilaos.com>
Date: Wed, 19 Jan 2022 14:20:19 +0200
Subject: [PATCH] Make Completions sorting a user option

* etc/NEWS: Document the new user option.
* lisp/minibuffer.el (completions-sort): Add new user option.
(minibuffer-completion-help): Implement it for the Completions buffer.
---
 etc/NEWS           |  6 ++++++
 lisp/minibuffer.el | 17 ++++++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/etc/NEWS b/etc/NEWS
index 47dbfba9c0..23b23e922c 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -418,6 +418,12 @@ When non-nil, the commands 'next-completion' and 'previous-completion'
 automatically wrap around on reaching the beginning or the end of
 the *Completions* buffer.
 
+*** New user option 'completions-sort'.
+Controls the sorting of the completion candidates in the *Completions*
+buffer.  Available styles are no sorting, alphabetical (the default),
+or a custom sort function.  The function takes and returns a list of
+completion candidate strings.
+
 ** Isearch and Replace
 
 +++
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index ab760a42d1..643e0f309e 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1169,6 +1169,18 @@ (defcustom completion-cycle-threshold nil
   :version "24.1"
   :type completion--cycling-threshold-type)
 
+(defcustom completions-sort 'alphabetical
+  "Sort candidates in the *Completions* buffer.
+
+The value can be nil to disable sorting, `alphabetical' for
+alphabetical sorting or a custom sorting function.  The sorting
+function takes and returns a list of completion candidate
+strings."
+  :type '(choice (const :tag "No sorting" nil)
+                 (const :tag "Alphabetical sorting" alphabetical)
+                 function :tag "Custom function")
+  :version "29.1")
+
 (defcustom completions-group nil
   "Enable grouping of completion candidates in the *Completions* buffer.
 See also `completions-group-format' and `completions-group-sort'."
@@ -2264,7 +2276,10 @@ (defun minibuffer-completion-help (&optional start end)
                       ;; same, but not always.
                       (setq completions (if sort-fun
                                             (funcall sort-fun completions)
-                                          (sort completions 'string-lessp)))
+                                          (pcase completions-sort
+                                            ('nil completions)
+                                            ('alphabetical (sort completions #'string-lessp))
+                                            (_ (funcall completions-sort completions)))))
 
                       ;; After sorting, group the candidates using the
                       ;; `group-function'.
-- 
2.34.1

bug#53362: 29.0.50; [PATCH] Make Completions sorting a user option

[Eli Zaretskii]

> From: Protesilaos Stavrou <info@protesilaos.com>
> Date: Thu, 20 Jan 2022 07:33:38 +0200
> 
> If you are still reading this, I attach the definitive patch.

Thanks, now installed on master.