From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eshel Yaron via "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#66948: [PATCH] Add Completion Preview mode Date: Mon, 06 Nov 2023 16:30:50 +0100 Message-ID: References: <87lebcqcof.fsf@posteo.net> <86a5rrcqd3.fsf@mail.linkov.net> Reply-To: Eshel Yaron Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="17393"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: dmitry@gutov.dev, 66948@debbugs.gnu.org, philipk@posteo.net, joaotavora@gmail.com To: Juri Linkov Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon Nov 06 16:31:39 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1r01Zj-0004Jc-1M for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 06 Nov 2023 16:31:39 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r01ZX-0006Yn-D2; Mon, 06 Nov 2023 10:31:27 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r01ZV-0006X1-EU for bug-gnu-emacs@gnu.org; Mon, 06 Nov 2023 10:31:25 -0500 Original-Received: from debbugs.gnu.org ([2001:470:142:5::43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1r01ZV-0004GI-5g for bug-gnu-emacs@gnu.org; Mon, 06 Nov 2023 10:31:25 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1r01a6-0008Cv-HL for bug-gnu-emacs@gnu.org; Mon, 06 Nov 2023 10:32:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eshel Yaron Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 06 Nov 2023 15:32:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 66948 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch X-Debbugs-Original-Cc: Dmitry Gutov , "Eshel Yaron via Bug reports for GNU Emacs, the Swiss army knife of text editors" , Philip Kaludercic , 66948@debbugs.gnu.org, =?UTF-8?Q?Jo=C3=A3o_?= =?UTF-8?Q?T=C3=A1vora?= Original-Received: via spool by 66948-submit@debbugs.gnu.org id=B66948.169928469531494 (code B ref 66948); Mon, 06 Nov 2023 15:32:02 +0000 Original-Received: (at 66948) by debbugs.gnu.org; 6 Nov 2023 15:31:35 +0000 Original-Received: from localhost ([127.0.0.1]:40388 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1r01Ze-0008Br-5S for submit@debbugs.gnu.org; Mon, 06 Nov 2023 10:31:35 -0500 Original-Received: from mail.eshelyaron.com ([107.175.124.16]:49794 helo=eshelyaron.com) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1r01Za-0008Bi-U3 for 66948@debbugs.gnu.org; Mon, 06 Nov 2023 10:31:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=eshelyaron.com; s=mail; t=1699284652; bh=/AfmX46Ft1uHOdTcVfiMb/nVtkvOlcSFM3hRUTdJZe4=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=Aq5I1WuBp7s8rS/1qwa2pwZhlzDleI7JVHNJUIorAmrdWTwPhsL7+DpQjDRN0KOFp oyb+N/SUVJofU/0eT/HKxKo9lg2enRJY6BoQw9dOz43qYXcl13UeeLdJ2zDy2yLaPx gInrQ3ABS8qTddOoj2H1t7S4Ud/eGsMwxM/kWkEuyyGUfjphtp6dse73hs000FQHp0 Zf2iPV9ernTrSlP2uYOPaRwcBeNEb5BPJGMwvjxrC7ITrxFY/LOVePdobdg4dIaLh8 SzTiR/0L6zt5knuVPKVEivzxgCryWZdECy2BW9q2qWa4XXeDPp3icuVbVEE/BpBoD+ 3ZgWNOPZofbjg== In-Reply-To: <86a5rrcqd3.fsf@mail.linkov.net> (Juri Linkov's message of "Mon, 06 Nov 2023 09:22:48 +0200") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:273876 Archived-At: --=-=-= Content-Type: text/plain Hi, Juri Linkov writes: >>> and that there is no option to cycle between inexact completions. >> >> That's interesting, can you elaborate about the use case that you have >> in mind? I thought about adding a command to do that, but I wasn't sure >> there'd be a good use case for it since you can always dismiss the >> preview (e.g. with `C-g`) and say `C-M-i` to pick another candidate. > > Is it possible to avoid typing `C-g` before typing `C-M-i` for the list > of completions? I mean that I'd prefer only TAB or RET to accept the > completion suggestion, but not `C-M-i`. Then when the proposed preview > is correct, TAB or RET will accept it, otherwise `C-M-i` will immediately > display a list of alternative completions. I'm attaching a new patch (v2) following Juri's and Philip's comments. The differences from the previous patch are: 1. TAB now accepts the completion suggestions when the preview is visible. RET remains untouched, as I find binding it by default too intrusive. 2. Completion Preview avoids altering the behavior of `completion-at-point` by default, so if you say `C-M-i` while the preview is visible you get the usual list of completion candidates. New user option `completion-preview-insert-on-completion` allows users to regain the behavior of my original patch, where `C-M-i` would insert accept the completion suggestion when the preview is visible. 3. New commands for cycling the candidate that the preview suggests. These are currently unbound by default, but I added a recommendation in the manual to bind `completion-preview-next-candidate` and `completion-preview-prev-candidate` to `M-n` and `M-p` in `completion-preview-active-mode-map`. That works nicely. If you try it out and have any other suggestions, please let me know. Here's the updated patch: --=-=-= Content-Type: text/x-patch; charset=utf-8 Content-Disposition: attachment; filename=v2-0001-Add-Completion-Preview-mode.patch Content-Transfer-Encoding: quoted-printable >From 2a83bc3b4b42f121fff49f688f116ce14fbc5742 Mon Sep 17 00:00:00 2001 From: Eshel Yaron Date: Thu, 2 Nov 2023 16:58:31 +0100 Subject: [PATCH v2] Add Completion Preview mode This adds a new minor mode, 'completion-preview-mode', that displays in-buffer completion suggestions with an inline "preview" overlay. * lisp/completion-preview.el: New file. * doc/emacs/programs.texi (Symbol Completion): Document it. * etc/NEWS: Announce it. --- doc/emacs/programs.texi | 83 ++++++++++++ etc/NEWS | 6 + lisp/completion-preview.el | 259 +++++++++++++++++++++++++++++++++++++ 3 files changed, 348 insertions(+) create mode 100644 lisp/completion-preview.el diff --git a/doc/emacs/programs.texi b/doc/emacs/programs.texi index 7746bc8bc23..41749bf9484 100644 --- a/doc/emacs/programs.texi +++ b/doc/emacs/programs.texi @@ -1701,6 +1701,89 @@ Symbol Completion In Text mode and related modes, @kbd{M-@key{TAB}} completes words based on the spell-checker's dictionary. @xref{Spelling}. =20 +@cindex completion preview +@cindex preview completion +@cindex suggestion preview +@cindex Completion Preview mode +@findex completion-preview-mode +@vindex completion-preview-mode + Completion Preview mode is a minor mode that shows you symbol +completion suggestions as type. When you enable Completion Preview +mode in a buffer (with @kbd{M-x completion-preview-mode}), Emacs +examines the text around point after certain commands you invoke and +automatically suggests a possible completion. Emacs displays this +suggestion with an inline preview right after point, so you see in +advance exactly how the text will look if you accept the completion +suggestion---that's why it's called a preview. + +For example, suppose that you have an Emacs Lisp buffer with the +following code: + +@lisp +(defun doit (foobarbaz) + fo@point{} +@end lisp + +If you type another @samp{o}, the preview appears after point, +suggesting that you complete the text to @samp{foobarbaz}: + +@lisp +(defun doit (foobarbaz) + foo@point{}barbaz +@end lisp + +Here, the text @samp{barbaz} after point is the completion preview. +You can accept the completion suggestion with @kbd{@key{TAB}} to +actually inserts @samp{barbaz} and move point after it: + +@lisp +(defun doit (foobarbaz) + foobarbaz@point{} +@end lisp + +If you want to ignore a completion suggestion, just go on editing or +moving around the buffer. Completion Preview mode continues to update +the suggestion as you type according to the text around point. + +@vindex completion-preview-active-mode-map +@findex completion-preview-prev-candidate +@findex completion-preview-next-candidate +The commands @code{completion-preview-next-candidate} and +@code{completion-preview-prev-candidate} allow you to cycle the +completion candidate that the preview suggests. These commands don't +have a default keybinding, but you can bind them, for example, to +@kbd{M-n} and @kbd{M-p} in @code{completion-preview-active-mode-map} +to have them handy whenever the preview is visible. + +@vindex completion-preview-exact-match-only +@vindex completion-preview-commands +@vindex completion-preview-minimum-symbol-length +If you set the user option @code{completion-preview-exact-match-only} +to non-@code{nil}, Completion Preview mode only suggests a completion +candidate when its the only possible completion for the (partial) +symbol at point. The user option @code{completion-preview-commands} +says which commands should trigger the completion preview, by default +that is only @code{self-insert-command}, which corresponds to when you +type regular characters in the buffer. The user option +@code{completion-preview-minimum-symbol-length} specifies a minimum +number of consecutive characters with word or symbol syntax that +should appear around point for Emacs to suggest a completion. By +default, this option is set to 3, so Emacs suggests a completion if +you type @samp{foo}, but typing just @samp{fo} doesn't trigger +completion preview. + +@vindex completion-preview-insert-on-completion +The user option @code{completion-preview-insert-on-completion} +controls what happens when you invoke @code{completion-at-point} while +the completion preview is visible. By default this option is +@code{nil}, which tells @code{completion-at-point} to ignore the +completion preview and show the list of completion candidates as +usual. If you set @code{completion-preview-insert-on-completion} to +non-@code{nil}, then @code{completion-at-point} inserts the preview +directly without looking for more candidates. To show the list of +candidates with this setting while the preview is visible, type +@kbd{C-g} to dismiss it before invoking @code{completion-at-point}. + @node MixedCase Words @section MixedCase Words @cindex camel case diff --git a/etc/NEWS b/etc/NEWS index c06a013466f..22513ccf98f 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -1020,6 +1020,12 @@ It highlights parens via =E2=80=98show-paren-mode=E2= =80=99 and =E2=80=98blink-matching-paren=E2=80=99 in a user-friendly way, avoids reporting alleged paren mismatches and makes sexp navigation more intuitive. =20 ++++ +*** New minor mode 'completion-preview-mode'. +This minor mode shows you symbol completion suggestions as you type, +using an inline preview. New user options in the 'completion-preview' +customization group control exactly when Emacs displays this preview. + --- ** 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/completion-preview.el b/lisp/completion-preview.el new file mode 100644 index 00000000000..834dbeffae4 --- /dev/null +++ b/lisp/completion-preview.el @@ -0,0 +1,259 @@ +;;; completion-preview.el --- Preview completion with inline overlay -*- = lexical-binding: t; -*- + +;; Copyright (C) 2023 Free Software Foundation, Inc. + +;; Author: Eshel Yaron +;; Maintainer: Eshel Yaron +;; Keywords: abbrev convenience + +;; This program is free software; you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; This program is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with this program. If not, see . + +;;; Commentary: + +;; This library provides the Completion Preview mode. This minor mode +;; displays the top completion candidate for the symbol at point in an +;; overlay after point. If you want to enable Completion Preview mode +;; in all programming modes, add the following to your Emacs init: +;; +;; (add-hook 'prog-mode-hook #'completion-preview-mode) +;; +;; Also check out the customization group `completion-preview` for +;; some user options that you may want to tweak. + +;;; Code: + +(defgroup completion-preview nil + "In-buffer completion preview." + :group 'completion) + +(defcustom completion-preview-exact-match-only nil + "Whether to show completion preview only when there is an exact match. + +If this option is non-nil, Completion Preview mode only shows the +preview overlay when there is exactly one completion candidate +that matches the symbol at point, otherwise it shows the top +candidate also when there are multiple matching candidates." + :type 'boolean) + +(defcustom completion-preview-commands '(self-insert-command + delete-backward-char + completion-preview-next-candidate + completion-preview-prev-candidate) + "List of commands that should trigger completion preview." + :type '(repeat (function :tag "Command" :value self-insert-command))) + +(defcustom completion-preview-minimum-symbol-length 3 + "Minimum length of the symbol at point for showing completion preview." + :type 'natnum) + +(defcustom completion-preview-hook + '(completion-preview-require-certain-commands + completion-preview-require-minimum-symbol-length) + "Hook for functions that determine whether to show preview completion. + +Completion Preview mode calls each of these functions in order +after each command, and only displays the completion preview when +all of the functions return non-nil." + :type 'hook) + +(defcustom completion-preview-insert-on-completion nil + "Whether \\[completion-at-point] inserts the previewed suggestion." + :type 'boolean) + +(defvar completion-preview-sort-function #'minibuffer--sort-by-length-alpha + "Sort function to use for choosing a completion candidate to preview.") + +(defface completion-preview + '((t :inherit shadow)) + "Face for completion preview overlay.") + +(defface completion-preview-exact + '((t :underline t :inherit completion-preview)) + "Face for exact completion preview overlay.") + +(defvar-keymap completion-preview-active-mode-map + :doc "Keymap for Completion Preview Active mode." + "C-i" #'completion-preview-insert + ;; "M-n" #'completion-preview-next-candidate + ;; "M-p" #'completion-preview-prev-candidate + ) + +(defvar-local completion-preview--overlay nil) + +(defun completion-preview-require-certain-commands () + "Check if `this-command' is one of `completion-preview-commands'." + (memq this-command completion-preview-commands)) + +(defun completion-preview-require-minimum-symbol-length () + "Check if the length of symbol at point is at least above a certain thre= shold. +`completion-preview-minimum-symbol-length' determines that threshold." + (pcase (bounds-of-thing-at-point 'symbol) + (`(,beg . ,end) + (<=3D completion-preview-minimum-symbol-length (- end beg))))) + +(defun completion-preview-hide () + "Hide the completion preview." + (when completion-preview--overlay + (delete-overlay completion-preview--overlay) + (setq completion-preview--overlay nil))) + +(defun completion-preview--make-overlay (pos string) + "Make a new completion preview overlay at POS showing STRING." + (if completion-preview--overlay + (move-overlay completion-preview--overlay pos pos) + (setq completion-preview--overlay (make-overlay pos pos))) + (add-text-properties 0 1 '(cursor 1) string) + (overlay-put completion-preview--overlay 'after-string string) + completion-preview--overlay) + +(defun completion-preview--get (prop) + (overlay-get completion-preview--overlay prop)) + +(define-minor-mode completion-preview-active-mode + "Mode for when the completion preview is active." + :interactive nil + (if completion-preview-active-mode + (add-hook 'completion-at-point-functions #'completion-preview--inser= t -1 t) + (remove-hook 'completion-at-point-functions #'completion-preview--inse= rt t) + (completion-preview-hide))) + +(defun completion-preview--exit-function (func) + "Return an exit function that hides the completion preview and calls FUN= C." + (lambda (&rest args) + (completion-preview-active-mode -1) + (when func (apply func args)))) + +(defun completion-preview--update () + "Update completion preview." + (pcase (let ((completion-preview-insert-on-completion nil)) + (run-hook-with-args-until-success 'completion-at-point-function= s)) + (`(,beg ,end ,table . ,plist) + (let* ((pred (plist-get plist :predicate)) + (exit-fn (completion-preview--exit-function + (plist-get plist :exit-function))) + (string (buffer-substring beg end)) + (md (completion-metadata string table pred)) + (sort-fn (or (completion-metadata-get md 'cycle-sort-function) + (completion-metadata-get md 'display-sort-functio= n) + completion-preview-sort-function)) + (all (completion-all-completions string table pred + (- (point) beg) md)) + (last (last all)) + (base (or (cdr last) 0)) + (bbeg (+ beg base)) + (prefix (substring string base))) + (when last + (setcdr last nil) + (let* ((filtered + (seq-filter (apply-partially #'string-prefix-p prefix) al= l)) + (sorted (funcall sort-fn filtered)) + (multi (cadr sorted)) ; multiple candidates + (cand (car sorted))) + (when (and cand (not (and multi completion-preview-exact-match-= only))) + (let* ((face (if multi 'completion-preview 'completion-previe= w-exact)) + (after (propertize (substring cand (length prefix)) 'f= ace face))) + (unless (string-empty-p after) + (let ((ov (completion-preview--make-overlay end after))) + (overlay-put ov 'completion-preview-beg bbeg) + (overlay-put ov 'completion-preview-end end) + (overlay-put ov 'completion-preview-index 0) + (overlay-put ov 'completion-preview-cands sorted) + (overlay-put ov 'completion-preview-exit-fn exit-fn)) + (completion-preview-active-mode)))))))))) + +(defun completion-preview--show () + "Show completion preview." + (when completion-preview-active-mode + (let* ((beg (completion-preview--get 'completion-preview-beg)) + (cands (completion-preview--get 'completion-preview-cands)) + (index (completion-preview--get 'completion-preview-index)) + (cand (nth index cands)) + (len (length cand)) + (end (+ beg len)) + (cur (point)) + (face (get-text-property 0 'face (completion-preview--get 'afte= r-string)))) + (if (and (< beg cur end) (string-prefix-p (buffer-substring beg cur)= cand)) + (overlay-put (completion-preview--make-overlay + cur (propertize (substring cand (- cur beg)) + 'face face)) + 'completion-preview-end cur) + (completion-preview-active-mode -1)))) + (while-no-input (completion-preview--update))) + +(defun completion-preview--post-command () + "Create, update or delete completion preview post last command." + (if (run-hook-with-args-until-failure 'completion-preview-hook) + (or (memq this-command '(completion-preview-next-candidate + completion-preview-prev-candidate)) + (completion-preview--show)) + (completion-preview-active-mode -1))) + +(defun completion-preview--insert () + "Completion at point function for inserting the current preview." + (when (and completion-preview-active-mode + completion-preview-insert-on-completion) + (list (completion-preview--get 'completion-preview-beg) + (completion-preview--get 'completion-preview-end) + (list (nth (completion-preview--get 'completion-preview-index) + (completion-preview--get 'completion-preview-cands))) + :exit-function (completion-preview--get 'completion-preview-exit= -fn)))) + +(defun completion-preview-insert () + "Insert the current completion preview." + (interactive) + (let ((completion-preview-insert-on-completion t)) + (completion-at-point))) + +(defun completion-preview-prev-candidate () + "Cycle the preview to the previous completion suggestion." + (interactive) + (completion-preview-next-candidate -1)) + +(defun completion-preview-next-candidate (direction) + "Cycle the preview to the next completion suggestion in DIRECTION. + +DIRECTION should be either 1 which means cycle forward, or -1 +which means cycle backward. Interactively, DIRECTION is the +prefix argument." + (interactive "p") + (when completion-preview-active-mode + (let* ((beg (completion-preview--get 'completion-preview-beg)) + (all (completion-preview--get 'completion-preview-cands)) + (cur (completion-preview--get 'completion-preview-index)) + (len (length all)) + (new (mod (+ cur direction) len)) + (str (nth new all)) + (pos (point))) + (while (or (<=3D (+ beg (length str)) pos) + (not (string-prefix-p (buffer-substring beg pos) str))) + (setq new (mod (+ new direction) len) str (nth new all))) + (let ((aft (propertize (substring str (- pos beg)) + 'face (if (< 1 len ) + 'completion-preview + 'completion-preview-exact)))) + (add-text-properties 0 1 '(cursor 1) aft) + (overlay-put completion-preview--overlay 'completion-preview-index= new) + (overlay-put completion-preview--overlay 'after-string aft))))) + +;;;###autoload +(define-minor-mode completion-preview-mode + "Show in-buffer completion preview as you type." + :lighter " CP" + (if completion-preview-mode + (add-hook 'post-command-hook #'completion-preview--post-command nil = t) + (remove-hook 'post-command-hook #'completion-preview--post-command t) + (completion-preview-active-mode -1))) + +(provide 'completion-preview) +;;; completion-preview.el ends here --=20 2.42.0 --=-=-=--