Package: emacs;
Reported by: Spencer Baugh <sbaugh <at> janestreet.com>
Date: Fri, 5 Apr 2024 12:43:02 UTC
Severity: wishlist
Tags: patch
Done: Eli Zaretskii <eliz <at> gnu.org>
Bug is archived. No further changes may be made.
Message #62 received at 70217 <at> debbugs.gnu.org (full text, mbox):
From: Spencer Baugh <sbaugh <at> janestreet.com> To: Eli Zaretskii <eliz <at> gnu.org> Cc: 70217 <at> debbugs.gnu.org, monnier <at> iro.umontreal.ca Subject: Re: bug#70217: [PATCH] Add substring-partial-completion style Date: Tue, 28 May 2024 14:16:30 -0400
[Message part 1 (text/plain, inline)]
Eli Zaretskii <eliz <at> gnu.org> writes:
>> From: Spencer Baugh <sbaugh <at> janestreet.com>
>> Cc: 70217 <at> debbugs.gnu.org, monnier <at> iro.umontreal.ca
>> Date: Tue, 28 May 2024 10:39:52 -0400
>>
>> Eli Zaretskii <eliz <at> gnu.org> writes:
>>
>> >> b/c does match bbb/ccc at the beginning, according to the
>> >> partial-completion rules. Explained as a glob, partial-completion turns
>> >> b/c into b*c which then can expand to bbb/ccc.
>> >
>> > Sorry, I don't understand what you are saying and how it addresses my
>> > concern. To me, this example contradicts what was explained in the
>> > documentation earlier, so we must clarify this, whether in the example
>> > or in the preceding descriptions. Please re-read how you described
>> > the effect of this option, and go from there.
>>
>> Okay, how about this completely reworked explanation? (It also changes
>> the name of the variable and inverts its effect)
>
> Thanks, this is more clear now.
> [snip]
> and (b) please do not use examples with repeated characters, because
> they can lead readers to make the wrong conclusions due to accidental
> situations. For example, AFAIU valid candidates for "b*/c*" include
> "bcdxyz/c1234" and also "b/x/y/z/c/1/2/3", but readers might
> mistakenly think that "b*" stands for a string made only of "b", or
> that there can be only one slash and it must precede "c". Avoiding
> repeated characters prevents such misunderstandings.
Excellent point, fixed.
> But please (a) don't use "glob" and file wildcard notation, use
> regexps instead;
True, I removed the word "glob", I agree that's confusing since
e.g. [a-z] or {foo,bar} are valid globs but not valid in
partial-completion.
Note however that "*" is literally valid syntax with partial-completion,
where as the regexp notation (".*") is not. The partial-completion
documentation already mentions this in (info "(emacs) Completion
Styles"). So I slightly reworded it and continued using "*".
[0001-Allow-customizing-partial-completion-to-be-more-like.patch (text/x-patch, inline)]
From b789f57aefd565bdbb8626fce129aa65e7a23af3 Mon Sep 17 00:00:00 2001
From: Spencer Baugh <sbaugh <at> janestreet.com>
Date: Sun, 26 May 2024 08:57:37 -0400
Subject: [PATCH] Allow customizing partial-completion to be more like
substring
The substring completion style completes "foo-bar" as "*foo-bar*". The
partial-completion completion style completes "foo-bar" as "foo*bar*".
Previously, it was not possible to get completion of "foo-bar" to act as
"*foo*bar*", e.g. combining the partial-completion and substring styles.
This would be especially useful for things like project-find-file.
Now it is possible by customizing the completion-pcm-anchored variable
to a non-nil value.
Furthermore, it's convenient to be able to run
regular (completion-pcm-anchored=t, non-substring) partial-completion
before running completion-pcm-anchored=nil partial-completion, since
the former provides more narrowly targeted completions.
It's possible to do this by customizing completion-styles. Just add
'(partial-completion ((completion-pcm-anchored t))) and
'(partial-completion ((completion-pcm-anchored nil))) in that order.
Then the completion machinery will first run partial-completion with
completion-pcm-anchored=t, and if that returns no completions, run
partial-completion with completion-pcm-anchored=nil.
* lisp/minibuffer.el (completion--nth-completion): Allow an element of
completion-styles to contain a list of bindings.
(completion-styles): Document that.
(completion-pcm-anchored): Add.
(completion-pcm--string->pattern): Check completion-pcm-anchored.
(bug#70217)
---
doc/emacs/mini.texi | 16 +++++++++++++--
etc/NEWS | 20 +++++++++++++++++++
lisp/minibuffer.el | 48 ++++++++++++++++++++++++++++++++++++++-------
3 files changed, 75 insertions(+), 9 deletions(-)
diff --git a/doc/emacs/mini.texi b/doc/emacs/mini.texi
index 4557f41c3f7..cfb5df4d586 100644
--- a/doc/emacs/mini.texi
+++ b/doc/emacs/mini.texi
@@ -535,8 +535,14 @@ Completion Styles
@vindex completion-styles
The list variable @code{completion-styles} specifies the completion
-styles to use. Each list element is the name of a completion style (a
-Lisp symbol). The available style symbols are stored in the variable
+styles to use. Each list element is either the name of a completion
+style (a Lisp symbol) or a list starting with the name of a completion
+style followed by @code{let}-style list of bindings which will be in
+effect for that completion style. Multiple elements of
+@code{completion-styles} can name the same completion style with
+different variable bindings.
+
+The available style symbols are stored in the variable
@code{completion-styles-alist} (@pxref{Completion Variables,,, elisp,
The Emacs Lisp Reference Manual}). The default completion styles are
(in order):
@@ -561,6 +567,12 @@ Completion Styles
@dfn{wildcard}---it matches any string of characters at the
corresponding position in the completion alternative.
+@vindex completion-pcm-leading-wildcard
+If @code{completion-pcm-leading-wildcard} is set to @code{t}, this style
+always acts as if a @dfn{wildcard} is present at the start of the
+minibuffer text, similar to the @code{substring} style. For example,
+@samp{l-m} will complete to @samp{emacs-lisp-mode}.
+
@item emacs22
@cindex @code{emacs22}, completion style
This completion style is similar to @code{basic}, except that it
diff --git a/etc/NEWS b/etc/NEWS
index d058acc3572..8eecc1d2aa3 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1848,6 +1848,26 @@ customization group control exactly when Emacs displays this preview.
'completion-preview-mode' is buffer-local, to enable it globally use
'global-completion-preview-mode'.
++++
+*** New user option 'completion-pcm-leading-wildcard'.
+This option configures how the partial-completion style does completion.
+It defaults to nil, which preserves the existing behavior. When it is set
+to t, the partial-completion style behaves more like the substring
+style, in that a string being completed can match against a candidate
+anywhere in the candidate string.
+
++++
+*** 'completion-styles' now can contain lists of bindings.
+In addition to being a symbol naming a completion style, an element of
+'completion-styles' can now be a list of the form '(STYLE ((VARIABLE
+VALUE) ...))' where STYLE is a symbol naming a completion style.
+VARIABLE will be bound to VALUE (without evaluating it) while the style
+is executing. This allows multiple references to the same style with
+different values for completion-affecting variables like
+'completion-pcm-leading-wildcard or 'completion-ignore-case'. This also
+applies for the styles configuration in 'completion-category-overrides'
+and 'completion-category-defaults'.
+
---
** The highly accessible Modus themes collection has eight items.
The 'modus-operandi' and 'modus-vivendi' are the main themes that have
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index f62cb2566b2..355fd23eed8 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1141,7 +1141,15 @@ completion-styles
;; and simply add "bar" to the end of the result.
emacs22)
"List of completion styles to use.
-The available styles are listed in `completion-styles-alist'.
+An element should be a symbol which is listed in
+`completion-styles-alist'.
+
+An element can also be a list of the form
+(STYLE ((VARIABLE VALUE) ...))
+STYLE must be a symbol listed in `completion-styles-alist', followed by
+a `let'-style list of variable/value pairs. VARIABLE will be bound to
+VALUE (without evaluating it) while the style is handling completion.
+This allows repeating the same style with different configurations.
Note that `completion-category-overrides' may override these
styles for specific categories, such as files, buffers, etc."
@@ -1284,11 +1292,18 @@ completion--nth-completion
(result-and-style
(seq-some
(lambda (style)
- (let ((probe (funcall
- (or (nth n (assq style completion-styles-alist))
- (error "Invalid completion style %s" style))
- string table pred point)))
- (and probe (cons probe style))))
+ (let (symbols values)
+ (when (consp style)
+ (dolist (binding (cadr style))
+ (push (car binding) symbols)
+ (push (cadr binding) values))
+ (setq style (car style)))
+ (cl-progv symbols values
+ (let ((probe (funcall
+ (or (nth n (assq style completion-styles-alist))
+ (error "Invalid completion style %s" style))
+ string table pred point)))
+ (and probe (cons probe style))))))
(completion--styles md)))
(adjust-fn (get (cdr result-and-style) 'completion--adjust-metadata)))
(when (and adjust-fn metadata)
@@ -3864,6 +3879,21 @@ completion-pcm--pattern-trivial-p
(setq trivial nil)))
trivial)))
+(defcustom completion-pcm-leading-wildcard nil
+ "If non-nil, partial-completion completes as if there's a leading wildcard.
+
+If nil (the default), the partial-completion style completes a string
+like \"o/t\" as if it was \"o*/t*\". This means \"one/two\" is a valid
+completion, but not \"zero/one/two\" or \"zeroone/two\".
+
+If non-nil, the partial-completion style completes \"o/t\" as if it was
+\"*o*/t*\". This means \"one/two\", \"zero/one/two\" and
+\"zeroone/two\" are all valid completions. Note that this can be slower
+to compute since less filtering of the completion candidates is
+possible."
+ :version "30.1"
+ :type 'boolean)
+
(defun completion-pcm--string->pattern (string &optional point)
"Split STRING into a pattern.
A pattern is a list where each element is either a string
@@ -3914,7 +3944,11 @@ completion-pcm--string->pattern
(when (> (length string) p0)
(if pending (push pending pattern))
(push (substring string p0) pattern))
- (nreverse pattern))))
+ (setq pattern (nreverse pattern))
+ (when completion-pcm-leading-wildcard
+ (when (stringp (car pattern))
+ (push 'prefix pattern)))
+ pattern)))
(defun completion-pcm--optimize-pattern (p)
;; Remove empty strings in a separate phase since otherwise a ""
--
2.39.3
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