djavu-asus/elpa/company-20230926.32/company-capf.el

   1 ;;; company-capf.el --- company-mode completion-at-point-functions backend -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 2013-2022  Free Software Foundation, Inc.
   4
   5 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software: you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  21
  22
  23 ;;; Commentary:
  24 ;;
  25 ;; The CAPF back-end provides a bridge to the standard
  26 ;; completion-at-point-functions facility, and thus can support any major mode
  27 ;; that defines a proper completion function, including emacs-lisp-mode,
  28 ;; css-mode and nxml-mode.
  29
  30 ;;; Code:
  31
  32 (require 'company)
  33 (require 'cl-lib)
  34
  35 ;; Amortizes several calls to a c-a-p-f from the same position.
  36 (defvar company--capf-cache nil)
  37
  38 ;; FIXME: Provide a way to save this info once in Company itself
  39 ;; (https://github.com/company-mode/company-mode/pull/845).
  40 (defvar-local company-capf--current-completion-data nil
  41   "Value last returned by `company-capf' when called with `candidates'.
  42 For most properties/actions, this is just what we need: the exact values
  43 that accompanied the completion table that's currently is use.
  44
  45 `company-capf', however, could be called at some different positions during
  46 a completion session (most importantly, by `company-sort-by-occurrence'),
  47 so we can't just use the preceding variable instead.")
  48
  49 (defun company--capf-data ()
  50   (let ((cache company--capf-cache))
  51     (if (and (equal (current-buffer) (car cache))
  52              (equal (point) (car (setq cache (cdr cache))))
  53              (equal (buffer-chars-modified-tick) (car (setq cache (cdr cache)))))
  54         (cadr cache)
  55       (let ((data (company--capf-data-real)))
  56         (setq company--capf-cache
  57               (list (current-buffer) (point) (buffer-chars-modified-tick) data))
  58         data))))
  59
  60 (defun company--contains (elt lst)
  61   (when-let ((cur (car lst)))
  62     (cond
  63      ((symbolp cur)
  64       (or (eq elt cur)
  65           (company--contains elt (cdr lst))))
  66      ((listp cur)
  67       (or (company--contains elt cur)
  68           (company--contains elt (cdr lst)))))))
  69
  70 (defun company--capf-data-real ()
  71   (cl-letf* (((default-value 'completion-at-point-functions)
  72               (if (company--contains 'company-etags company-backends)
  73                   ;; Ignore tags-completion-at-point-function because it subverts
  74                   ;; company-etags in the default value of company-backends, where
  75                   ;; the latter comes later.
  76                   (remove 'tags-completion-at-point-function
  77                           (default-value 'completion-at-point-functions))
  78                 (default-value 'completion-at-point-functions)))
  79              (completion-at-point-functions (company--capf-workaround))
  80              (data (run-hook-wrapped 'completion-at-point-functions
  81                                      ;; Ignore misbehaving functions.
  82                                      #'company--capf-wrapper 'optimist)))
  83     (when (and (consp (cdr data)) (integer-or-marker-p (nth 1 data))) data)))
  84
  85 (defun company--capf-wrapper (fun which)
  86   (let ((buffer-read-only t)
  87         (inhibit-read-only nil)
  88         (completion-in-region-function
  89          (lambda (beg end coll pred)
  90            (throw 'company--illegal-completion-in-region
  91                   (list fun beg end coll :predicate pred)))))
  92     (catch 'company--illegal-completion-in-region
  93       (condition-case nil
  94           (completion--capf-wrapper fun which)
  95         (buffer-read-only nil)))))
  96
  97 (declare-function python-shell-get-process "python")
  98
  99 (defun company--capf-workaround ()
 100   ;; For http://debbugs.gnu.org/cgi/bugreport.cgi?bug=18067
 101   (if (or (not (listp completion-at-point-functions))
 102           (not (memq 'python-completion-complete-at-point completion-at-point-functions))
 103           (python-shell-get-process))
 104       completion-at-point-functions
 105     (remq 'python-completion-complete-at-point completion-at-point-functions)))
 106
 107 (defun company-capf--save-current-data (data)
 108   (setq company-capf--current-completion-data data)
 109   (add-hook 'company-after-completion-hook
 110             #'company-capf--clear-current-data nil t))
 111
 112 (defun company-capf--clear-current-data (_ignored)
 113   (setq company-capf--current-completion-data nil))
 114
 115 (defvar-local company-capf--sorted nil)
 116
 117 (defun company-capf (command &optional arg &rest _args)
 118   "`company-mode' backend using `completion-at-point-functions'."
 119   (interactive (list 'interactive))
 120   (pcase command
 121     (`interactive (company-begin-backend 'company-capf))
 122     (`prefix
 123      (let ((res (company--capf-data)))
 124        (when res
 125          (let ((length (plist-get (nthcdr 4 res) :company-prefix-length))
 126                (prefix (buffer-substring-no-properties (nth 1 res) (point))))
 127            (cond
 128             ((> (nth 2 res) (point)) 'stop)
 129             (length (cons prefix length))
 130             (t prefix))))))
 131     (`candidates
 132      (company-capf--candidates arg))
 133     (`sorted
 134      company-capf--sorted)
 135     (`match
 136      ;; Ask the for the `:company-match' function.  If that doesn't help,
 137      ;; fallback to sniffing for face changes to get a suitable value.
 138      (let ((f (plist-get (nthcdr 4 company-capf--current-completion-data)
 139                          :company-match)))
 140        (if f (funcall f arg)
 141          (let* ((match-start nil) (pos -1)
 142                 (prop-value nil)  (faces nil)
 143                 (has-face-p nil)  chunks
 144                 (limit (length arg)))
 145            (while (< pos limit)
 146              (setq pos
 147                    (if (< pos 0) 0 (next-property-change pos arg limit)))
 148              (setq prop-value (or
 149                                (get-text-property pos 'face arg)
 150                                (get-text-property pos 'font-lock-face arg))
 151                    faces (if (listp prop-value) prop-value (list prop-value))
 152                    has-face-p (memq 'completions-common-part faces))
 153              (cond ((and (not match-start) has-face-p)
 154                     (setq match-start pos))
 155                    ((and match-start (not has-face-p))
 156                     (push (cons match-start pos) chunks)
 157                     (setq match-start nil))))
 158            (nreverse chunks)))))
 159     (`duplicates t)
 160     (`no-cache t)   ;Not much can be done here, as long as we handle
 161                     ;non-prefix matches.
 162     (`meta
 163      (let ((f (plist-get (nthcdr 4 company-capf--current-completion-data)
 164                          :company-docsig)))
 165        (when f (funcall f arg))))
 166     (`doc-buffer
 167      (let ((f (plist-get (nthcdr 4 company-capf--current-completion-data)
 168                          :company-doc-buffer)))
 169        (when f (funcall f arg))))
 170     (`location
 171      (let ((f (plist-get (nthcdr 4 company-capf--current-completion-data)
 172                          :company-location)))
 173        (when f (funcall f arg))))
 174     (`annotation
 175      (company-capf--annotation arg))
 176     (`kind
 177      (let ((f (plist-get (nthcdr 4 company-capf--current-completion-data)
 178                          :company-kind)))
 179        (when f (funcall f arg))))
 180     (`deprecated
 181      (let ((f (plist-get (nthcdr 4 company-capf--current-completion-data)
 182                          :company-deprecated)))
 183        (when f (funcall f arg))))
 184     (`require-match
 185      (plist-get (nthcdr 4 (company--capf-data)) :company-require-match))
 186     (`init nil)      ;Don't bother: plenty of other ways to initialize the code.
 187     (`post-completion
 188      (company--capf-post-completion arg))
 189     ))
 190
 191 (defun company-capf--annotation (arg)
 192   (let* ((f (or (plist-get (nthcdr 4 company-capf--current-completion-data)
 193                            :annotation-function)
 194                 ;; FIXME: Add a test.
 195                 (cdr (assq 'annotation-function
 196                            (completion-metadata
 197                             (buffer-substring (nth 1 company-capf--current-completion-data)
 198                                               (nth 2 company-capf--current-completion-data))
 199                             (nth 3 company-capf--current-completion-data)
 200                             (plist-get (nthcdr 4 company-capf--current-completion-data)
 201                                        :predicate))))))
 202          (annotation (when f (funcall f arg))))
 203     (if (and company-format-margin-function
 204              (equal annotation " <f>") ; elisp-completion-at-point, pre-icons
 205              (plist-get (nthcdr 4 company-capf--current-completion-data)
 206                         :company-kind))
 207         nil
 208       annotation)))
 209
 210 (defun company-capf--candidates (input)
 211   (let ((res (company--capf-data)))
 212     (company-capf--save-current-data res)
 213     (when res
 214       (let* ((table (nth 3 res))
 215              (pred (plist-get (nthcdr 4 res) :predicate))
 216              (meta (completion-metadata
 217                     (buffer-substring (nth 1 res) (nth 2 res))
 218                     table pred))
 219              (candidates (completion-all-completions input table pred
 220                                                      (length input)
 221                                                      meta))
 222              (sortfun (cdr (assq 'display-sort-function meta)))
 223              (last (last candidates))
 224              (base-size (and (numberp (cdr last)) (cdr last))))
 225         (when base-size
 226           (setcdr last nil))
 227         (setq company-capf--sorted (functionp sortfun))
 228         (when sortfun
 229           (setq candidates (funcall sortfun candidates)))
 230         (if (not (zerop (or base-size 0)))
 231             (let ((before (substring input 0 base-size)))
 232               (mapcar (lambda (candidate)
 233                         (concat before candidate))
 234                       candidates))
 235           candidates)))))
 236
 237 (defun company--capf-post-completion (arg)
 238   (let* ((res company-capf--current-completion-data)
 239          (exit-function (plist-get (nthcdr 4 res) :exit-function))
 240          (table (nth 3 res)))
 241     (if exit-function
 242         ;; We can more or less know when the user is done with completion,
 243         ;; so we do something different than `completion--done'.
 244         (funcall exit-function arg
 245                  ;; FIXME: Should probably use an additional heuristic:
 246                  ;; completion-at-point doesn't know when the user picked a
 247                  ;; particular candidate explicitly (it only checks whether
 248                  ;; further completions exist). Whereas company user can press
 249                  ;; RET (or use implicit completion with company-tng).
 250                  (if (= (car (completion-boundaries arg table nil ""))
 251                         (length arg))
 252                      'sole
 253                    'finished)))))
 254
 255 (provide 'company-capf)
 256
 257 ;;; company-capf.el ends here