;;; company-dabbrev.el --- dabbrev-like company-mode completion backend -*- lexical-binding: t -*-
;; Copyright (C) 2009, 2011, 2014, 2015, 2016 Free Software Foundation, Inc.
;; Author: Nikolaj Schumacher
;; This file is part of GNU Emacs.
;; GNU Emacs 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.
;; GNU Emacs 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 GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;
;;; Code:
(require 'company)
(require 'cl-lib)
(defgroup company-dabbrev nil
"dabbrev-like completion backend."
:group 'company)
(defcustom company-dabbrev-other-buffers 'all
"Determines whether `company-dabbrev' should search other buffers.
If `all', search all other buffers, except the ignored ones. If t, search
buffers with the same major mode. See also `company-dabbrev-time-limit'."
:type '(choice (const :tag "Off" nil)
(const :tag "Same major mode" t)
(const :tag "All" all)))
(defcustom company-dabbrev-ignore-buffers "\\`[ *]"
"Regexp matching the names of buffers to ignore.
Or a function that returns non-nil for such buffers."
:type '(choice (regexp :tag "Regexp")
(function :tag "Predicate"))
:package-version '(company . "0.9.0"))
(defcustom company-dabbrev-time-limit .1
"Determines how many seconds `company-dabbrev' should look for matches."
:type '(choice (const :tag "Off" nil)
(number :tag "Seconds")))
(defcustom company-dabbrev-char-regexp "\\sw"
"A regular expression matching the characters `company-dabbrev' looks for."
:type 'regexp)
(defcustom company-dabbrev-ignore-case 'keep-prefix
"Non-nil to ignore case when collecting completion candidates.
When it's `keep-prefix', the text before point will remain unchanged after
candidate is inserted, even some of its characters have different case."
:type '(choice
(const :tag "Don't ignore case" nil)
(const :tag "Ignore case" t)
(const :tag "Keep case before point" keep-prefix)))
(defcustom company-dabbrev-downcase 'case-replace
"Whether to downcase the returned candidates.
The value of nil means keep them as-is.
`case-replace' means use the value of `case-replace'.
Any other value means downcase.
If you set this value to nil, you may also want to set
`company-dabbrev-ignore-case' to any value other than `keep-prefix'."
:type '(choice
(const :tag "Keep as-is" nil)
(const :tag "Downcase" t)
(const :tag "Use case-replace" case-replace)))
(defcustom company-dabbrev-minimum-length 4
"The minimum length for the completion candidate to be included.
This variable affects both `company-dabbrev' and `company-dabbrev-code'."
:type 'integer
:package-version '(company . "0.8.3"))
(defcustom company-dabbrev-ignore-invisible nil
"Non-nil to skip invisible text."
:type 'boolean
:package-version '(company . "0.9.0"))
(defmacro company-dabbrev--time-limit-while (test start limit freq &rest body)
(declare (indent 3) (debug t))
`(let ((company-time-limit-while-counter 0))
(catch 'done
(while ,test
,@body
(and ,limit
(= (cl-incf company-time-limit-while-counter) ,freq)
(setq company-time-limit-while-counter 0)
(> (float-time (time-since ,start)) ,limit)
(throw 'done 'company-time-out))))))
(defun company-dabbrev--make-regexp ()
(concat "\\(?:" company-dabbrev-char-regexp "\\)+"))
(defun company-dabbrev--search-buffer (regexp pos symbols start limit
ignore-comments)
(save-excursion
(cl-labels ((maybe-collect-match
()
(let ((match (match-string-no-properties 0)))
(when (and (>= (length match) company-dabbrev-minimum-length)
(not (and company-dabbrev-ignore-invisible
(invisible-p (match-beginning 0)))))
(push match symbols)))))
(goto-char (if pos (1- pos) (point-min)))
;; Search before pos.
(let ((tmp-end (point)))
(company-dabbrev--time-limit-while (and (not (input-pending-p))
(> tmp-end (point-min)))
start limit 1
(ignore-errors
(forward-char -10000))
(forward-line 0)
(save-excursion
;; Before, we used backward search, but it matches non-greedily, and
;; that forced us to use the "beginning/end of word" anchors in
;; `company-dabbrev--make-regexp'. It's also about 2x slower.
(while (and (not (input-pending-p))
(re-search-forward regexp tmp-end t))
(if (and ignore-comments (save-match-data (company-in-string-or-comment)))
(re-search-forward "\\s>\\|\\s!\\|\\s\"" tmp-end t)
(maybe-collect-match))))
(setq tmp-end (point))))
(goto-char (or pos (point-min)))
;; Search after pos.
(company-dabbrev--time-limit-while (and (not (input-pending-p))
(re-search-forward regexp nil t))
start limit 25
(if (and ignore-comments (save-match-data (company-in-string-or-comment)))
(re-search-forward "\\s>\\|\\s!\\|\\s\"" nil t)
(maybe-collect-match)))
symbols)))
(defun company-dabbrev--search (regexp &optional limit other-buffer-modes
ignore-comments)
(let* ((start (current-time))
(symbols (company-dabbrev--search-buffer regexp (point) nil start limit
ignore-comments)))
(when other-buffer-modes
(cl-dolist (buffer (delq (current-buffer) (buffer-list)))
(unless (if (stringp company-dabbrev-ignore-buffers)
(string-match-p company-dabbrev-ignore-buffers
(buffer-name buffer))
(funcall company-dabbrev-ignore-buffers buffer))
(with-current-buffer buffer
(when (or (eq other-buffer-modes 'all)
(apply #'derived-mode-p other-buffer-modes))
(setq symbols
(company-dabbrev--search-buffer regexp nil symbols start
limit ignore-comments)))))
(and limit
(> (float-time (time-since start)) limit)
(cl-return))))
symbols))
(defun company-dabbrev--prefix ()
;; Not in the middle of a word.
(unless (looking-at company-dabbrev-char-regexp)
;; Emacs can't do greedy backward-search.
(company-grab-line (format "\\(?:^\\| \\)[^ ]*?\\(\\(?:%s\\)*\\)"
company-dabbrev-char-regexp)
1)))
(defun company-dabbrev--filter (prefix candidates)
(let ((completion-ignore-case company-dabbrev-ignore-case))
(all-completions prefix candidates)))
;;;###autoload
(defun company-dabbrev (command &optional arg &rest ignored)
"dabbrev-like `company-mode' completion backend."
(interactive (list 'interactive))
(cl-case command
(interactive (company-begin-backend 'company-dabbrev))
(prefix (company-dabbrev--prefix))
(candidates
(let* ((case-fold-search company-dabbrev-ignore-case)
(words (company-dabbrev--search (company-dabbrev--make-regexp)
company-dabbrev-time-limit
(pcase company-dabbrev-other-buffers
(`t (list major-mode))
(`all `all))))
(downcase-p (if (eq company-dabbrev-downcase 'case-replace)
case-replace
company-dabbrev-downcase)))
(setq words (company-dabbrev--filter arg words))
(if downcase-p
(mapcar 'downcase words)
words)))
(ignore-case company-dabbrev-ignore-case)
(duplicates t)))
(provide 'company-dabbrev)
;;; company-dabbrev.el ends here
