company-sort-by-occurrence: handle cons prefixes

[gnu-emacs-elpa] / company.el

;;; company.el --- Modular in-buffer completion framework  -*- lexical-binding: t -*-

;; Copyright (C) 2009-2014  Free Software Foundation, Inc.

;; Author: Nikolaj Schumacher
;; Maintainer: Dmitry Gutov <dgutov@yandex.ru>
;; Version: 0.6.14
;; Keywords: abbrev, convenience, matching
;; URL: http://company-mode.github.io/
;; Compatibility: GNU Emacs 22.x, GNU Emacs 23.x, GNU Emacs 24.x

;; 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:
;;
;; Company is a modular completion mechanism.  Modules for retrieving completion
;; candidates are called back-ends, modules for displaying them are front-ends.
;;
;; Company comes with many back-ends, e.g. `company-elisp'.  These are
;; distributed in separate files and can be used individually.
;;
;; Place company.el and the back-ends you want to use in a directory and add the
;; following to your .emacs:
;; (add-to-list 'load-path "/path/to/company")
;; (autoload 'company-mode "company" nil t)
;;
;; Enable company-mode with M-x company-mode.  For further information look at
;; the documentation for `company-mode' (C-h f company-mode RET)
;;
;; If you want to start a specific back-end, call it interactively or use
;; `company-begin-backend'.  For example:
;; M-x company-abbrev will prompt for and insert an abbrev.
;;
;; To write your own back-end, look at the documentation for `company-backends'.
;; Here is a simple example completing "foo":
;;
;; (defun company-my-backend (command &optional arg &rest ignored)
;;   (case command
;;     (prefix (when (looking-back "foo\\>")
;;               (match-string 0)))
;;     (candidates (list "foobar" "foobaz" "foobarbaz"))
;;     (meta (format "This value is named %s" arg))))
;;
;; Sometimes it is a good idea to mix several back-ends together, for example to
;; enrich gtags with dabbrev-code results (to emulate local variables).
;; To do this, add a list with both back-ends as an element in company-backends.
;;
;; Known Issues:
;; When point is at the very end of the buffer, the pseudo-tooltip appears very
;; wrong, unless company is allowed to temporarily insert a fake newline.
;; This behavior is enabled by `company-end-of-buffer-workaround'.
;;
;;; Change Log:
;;
;; See NEWS.md in the repository.

;;; Code:

(eval-when-compile (require 'cl))

;; FIXME: Use `user-error'.
(add-to-list 'debug-ignored-errors "^.* frontend cannot be used twice$")
(add-to-list 'debug-ignored-errors "^Echo area cannot be used twice$")
(add-to-list 'debug-ignored-errors "^No \\(document\\|loc\\)ation available$")
(add-to-list 'debug-ignored-errors "^Company not ")
(add-to-list 'debug-ignored-errors "^No candidate number ")
(add-to-list 'debug-ignored-errors "^Cannot complete at point$")
(add-to-list 'debug-ignored-errors "^No other back-end$")

(defgroup company nil
  "Extensible inline text completion mechanism"
  :group 'abbrev
  :group 'convenience
  :group 'matching)

(defface company-tooltip
  '((default :foreground "black")
    (((class color) (min-colors 88) (background light))
     (:background "cornsilk"))
    (((class color) (min-colors 88) (background dark))
     (:background "yellow")))
  "Face used for the tooltip.")

(defface company-tooltip-selection
  '((default :inherit company-tooltip)
    (((class color) (min-colors 88) (background light))
     (:background "light blue"))
    (((class color) (min-colors 88) (background dark))
     (:background "orange1"))
    (t (:background "green")))
  "Face used for the selection in the tooltip.")

(defface company-tooltip-mouse
  '((default :inherit highlight))
  "Face used for the tooltip item under the mouse.")

(defface company-tooltip-common
  '((default :inherit company-tooltip)
    (((background light))
     :foreground "darkred")
    (((background dark))
     :foreground "red"))
  "Face used for the common completion in the tooltip.")

(defface company-tooltip-common-selection
  '((default :inherit company-tooltip-selection)
    (((background light))
     :foreground "darkred")
    (((background dark))
     :foreground "red"))
  "Face used for the selected common completion in the tooltip.")

(defface company-scrollbar-fg
  '((((background light))
     :background "darkred")
    (((background dark))
     :background "red"))
  "Face used for the tooltip scrollbar thumb.")

(defface company-scrollbar-bg
  '((default :inherit company-tooltip)
    (((background light))
     :background "wheat")
    (((background dark))
     :background "gold"))
  "Face used for the tooltip scrollbar background.")

(defface company-preview
  '((t :background "blue4"
       :foreground "wheat"))
  "Face used for the completion preview.")

(defface company-preview-common
  '((t :inherit company-preview
       :foreground "red"))
  "Face used for the common part of the completion preview.")

(defface company-preview-search
  '((t :inherit company-preview
       :background "blue1"))
  "Face used for the search string in the completion preview.")

(defface company-echo nil
  "Face used for completions in the echo area.")

(defface company-echo-common
  '((((background dark)) (:foreground "firebrick1"))
    (((background light)) (:background "firebrick4")))
  "Face used for the common part of completions in the echo area.")

(defun company-frontends-set (variable value)
  ;; uniquify
  (let ((remainder value))
    (setcdr remainder (delq (car remainder) (cdr remainder))))
  (and (memq 'company-pseudo-tooltip-unless-just-one-frontend value)
       (memq 'company-pseudo-tooltip-frontend value)
       (error "Pseudo tooltip frontend cannot be used twice"))
  (and (memq 'company-preview-if-just-one-frontend value)
       (memq 'company-preview-frontend value)
       (error "Preview frontend cannot be used twice"))
  (and (memq 'company-echo value)
       (memq 'company-echo-metadata-frontend value)
       (error "Echo area cannot be used twice"))
  ;; preview must come last
  (dolist (f '(company-preview-if-just-one-frontend company-preview-frontend))
    (when (memq f value)
      (setq value (append (delq f value) (list f)))))
  (set variable value))

(defcustom company-frontends '(company-pseudo-tooltip-unless-just-one-frontend
                               company-preview-if-just-one-frontend
                               company-echo-metadata-frontend)
  "The list of active front-ends (visualizations).
Each front-end is a function that takes one argument.  It is called with
one of the following arguments:

`show': When the visualization should start.

`hide': When the visualization should end.

`update': When the data has been updated.

`pre-command': Before every command that is executed while the
visualization is active.

`post-command': After every command that is executed while the
visualization is active.

The visualized data is stored in `company-prefix', `company-candidates',
`company-common', `company-selection', `company-point' and
`company-search-string'."
  :set 'company-frontends-set
  :type '(repeat (choice (const :tag "echo" company-echo-frontend)
                         (const :tag "echo, strip common"
                                company-echo-strip-common-frontend)
                         (const :tag "show echo meta-data in echo"
                                company-echo-metadata-frontend)
                         (const :tag "pseudo tooltip"
                                company-pseudo-tooltip-frontend)
                         (const :tag "pseudo tooltip, multiple only"
                                company-pseudo-tooltip-unless-just-one-frontend)
                         (const :tag "preview" company-preview-frontend)
                         (const :tag "preview, unique only"
                                company-preview-if-just-one-frontend)
                         (function :tag "custom function" nil))))

(defcustom company-tooltip-limit 10
  "The maximum number of candidates in the tooltip"
  :type 'integer)

(defcustom company-tooltip-minimum 6
  "The minimum height of the tooltip.
If this many lines are not available, prefer to display the tooltip above."
  :type 'integer)

(defcustom company-tooltip-margin 1
  "Width of margin columns to show around the toolip."
  :type 'integer)

(defcustom company-tooltip-offset-display 'scrollbar
  "Method using which the tooltip displays scrolling position.
`scrollbar' means draw a scrollbar to the right of the items.
`lines' means wrap items in lines with \"before\" and \"after\" counters."
  :type '(choice (const :tag "Scrollbar" scrollbar)
                 (const :tag "Two lines" lines)))

(defvar company-safe-backends
  '((company-abbrev . "Abbrev")
    (company-capf . "completion-at-point-functions")
    (company-clang . "Clang")
    (company-cmake . "CMake")
    (company-css . "CSS")
    (company-dabbrev . "dabbrev for plain text")
    (company-dabbrev-code . "dabbrev for code")
    (company-eclim . "Eclim (an Eclipse interface)")
    (company-elisp . "Emacs Lisp")
    (company-etags . "etags")
    (company-files . "Files")
    (company-gtags . "GNU Global")
    (company-ispell . "Ispell")
    (company-keywords . "Programming language keywords")
    (company-nxml . "nxml")
    (company-oddmuse . "Oddmuse")
    (company-pysmell . "PySmell")
    (company-ropemacs . "ropemacs")
    (company-semantic . "Semantic")
    (company-tempo . "Tempo templates")
    (company-xcode . "Xcode")))
(put 'company-safe-backends 'risky-local-variable t)

(defun company-safe-backends-p (backends)
  (and (consp backends)
       (not (dolist (backend backends)
              (unless (if (consp backend)
                          (company-safe-backends-p backend)
                        (assq backend company-safe-backends))
                (return t))))))

(defvar company--include-capf (version< "24.3.50" emacs-version))

(defcustom company-backends `(,@(unless company--include-capf
                                  (list 'company-elisp))
                              company-nxml company-css
                              company-eclim company-semantic company-clang
                              company-xcode company-ropemacs company-cmake
                              ,@(when company--include-capf
                                  (list 'company-capf))
                              (company-gtags company-etags company-dabbrev-code
                               company-keywords)
                              company-oddmuse company-files company-dabbrev)
  "The list of active back-ends (completion engines).
Each list elements can itself be a list of back-ends.  In that case their
completions are merged.  Otherwise only the first matching back-end returns
results.

`company-begin-backend' can be used to start a specific back-end,
`company-other-backend' will skip to the next matching back-end in the list.

Each back-end is a function that takes a variable number of arguments.
The first argument is the command requested from the back-end.  It is one
of the following:

`prefix': The back-end should return the text to be completed.  It must be
text immediately before point.  Returning nil passes control to the next
back-end.  The function should return `stop' if it should complete but
cannot \(e.g. if it is in the middle of a string\).  Instead of a string,
the back-end may return a cons where car is the prefix and cdr is used in
`company-minimum-prefix-length' test. It's either number or t, in which
case the test automatically succeeds.

`candidates': The second argument is the prefix to be completed.  The
return value should be a list of candidates that start with the prefix.

Optional commands:

`sorted': Return t here to indicate that the candidates are sorted and will
not need to be sorted again.

`duplicates': If non-nil, company will take care of removing duplicates
from the list.

`no-cache': Usually company doesn't ask for candidates again as completion
progresses, unless the back-end returns t for this command.  The second
argument is the latest prefix.

`meta': The second argument is a completion candidate.  Return a (short)
documentation string for it.

`doc-buffer': The second argument is a completion candidate.  Return a
buffer with documentation for it.  Preferably use `company-doc-buffer',

`location': The second argument is a completion candidate.  Return the cons
of buffer and buffer location, or of file and line number where the
completion candidate was defined.

`require-match': If this returns t, the user is not allowed to enter
anything not offered as a candidate.  Use with care!  The default value nil
gives the user that choice with `company-require-match'.  Return value
`never' overrides that option the other way around.

`init': Called once for each buffer. The back-end can check for external
programs and files and load any required libraries.  Raising an error here
will show up in message log once, and the back-end will not be used for
completion.

`post-completion': Called after a completion candidate has been inserted
into the buffer.  The second argument is the candidate.  Can be used to
modify it, e.g. to expand a snippet.

The back-end should return nil for all commands it does not support or
does not know about.  It should also be callable interactively and use
`company-begin-backend' to start itself in that case."
  :type `(repeat
          (choice
           :tag "Back-end"
           ,@(mapcar (lambda (b) `(const :tag ,(cdr b) ,(car b)))
                     company-safe-backends)
           (symbol :tag "User defined")
           (repeat :tag "Merged Back-ends"
                   (choice :tag "Back-end"
                           ,@(mapcar (lambda (b)
                                       `(const :tag ,(cdr b) ,(car b)))
                                     company-safe-backends)
                           (symbol :tag "User defined"))))))

(put 'company-backends 'safe-local-variable 'company-safe-backends-p)

(defcustom company-transformers nil
  "Functions to change the list of candidates received from backends,
after sorting and removal of duplicates (if appropriate).
Each function gets called with the return value of the previous one."
  :type '(repeat
          (choice
           (const :tag "Sort by occurrence" 'company-sort-by-occurrence)
           (function :tag "Custom function"))))

(defcustom company-completion-started-hook nil
  "Hook run when company starts completing.
The hook is called with one argument that is non-nil if the completion was
started manually."
  :type 'hook)

(defcustom company-completion-cancelled-hook nil
  "Hook run when company cancels completing.
The hook is called with one argument that is non-nil if the completion was
aborted manually."
  :type 'hook)

(defcustom company-completion-finished-hook nil
  "Hook run when company successfully completes.
The hook is called with the selected candidate as an argument.

If you indend to use it to post-process candidates from a specific
back-end, consider using the `post-completion' command instead."
  :type 'hook)

(defcustom company-minimum-prefix-length 3
  "The minimum prefix length for idle completion."
  :type '(integer :tag "prefix length"))

(defcustom company-require-match 'company-explicit-action-p
  "If enabled, disallow non-matching input.
This can be a function do determine if a match is required.

This can be overridden by the back-end, if it returns t or `never' to
`require-match'.  `company-auto-complete' also takes precedence over this."
  :type '(choice (const :tag "Off" nil)
                 (function :tag "Predicate function")
                 (const :tag "On, if user interaction took place"
                        'company-explicit-action-p)
                 (const :tag "On" t)))

(defcustom company-auto-complete nil
  "Determines when to auto-complete.
If this is enabled, all characters from `company-auto-complete-chars'
trigger insertion of the selected completion candidate.
This can also be a function."
  :type '(choice (const :tag "Off" nil)
                 (function :tag "Predicate function")
                 (const :tag "On, if user interaction took place"
                        'company-explicit-action-p)
                 (const :tag "On" t)))

(defcustom company-auto-complete-chars '(?\  ?\) ?.)
  "Determines which characters trigger auto-completion.
See `company-auto-complete'.  If this is a string, each string character
tiggers auto-completion.  If it is a list of syntax description characters (see
`modify-syntax-entry'), all characters with that syntax auto-complete.

This can also be a function, which is called with the new input and should
return non-nil if company should auto-complete.

A character that is part of a valid candidate never triggers auto-completion."
  :type '(choice (string :tag "Characters")
                 (set :tag "Syntax"
                      (const :tag "Whitespace" ?\ )
                      (const :tag "Symbol" ?_)
                      (const :tag "Opening parentheses" ?\()
                      (const :tag "Closing parentheses" ?\))
                      (const :tag "Word constituent" ?w)
                      (const :tag "Punctuation." ?.)
                      (const :tag "String quote." ?\")
                      (const :tag "Paired delimiter." ?$)
                      (const :tag "Expression quote or prefix operator." ?\')
                      (const :tag "Comment starter." ?<)
                      (const :tag "Comment ender." ?>)
                      (const :tag "Character-quote." ?/)
                      (const :tag "Generic string fence." ?|)
                      (const :tag "Generic comment fence." ?!))
                 (function :tag "Predicate function")))

(defcustom company-idle-delay .7
  "The idle delay in seconds until completion starts automatically.
A value of nil means no idle completion, t means show candidates
immediately when a prefix of `company-minimum-prefix-length' is reached."
  :type '(choice (const :tag "never (nil)" nil)
                 (const :tag "immediate (t)" t)
                 (number :tag "seconds")))

(defcustom company-begin-commands '(self-insert-command org-self-insert-command)
  "A list of commands after which idle completion is allowed.
If this is t, it can show completions after any command.  See
`company-idle-delay'.

Alternatively, any command with a non-nil `company-begin' property is
treated as if it was on this list."
  :type '(choice (const :tag "Any command" t)
                 (const :tag "Self insert command" '(self-insert-command))
                 (repeat :tag "Commands" function)))

(defcustom company-show-numbers nil
  "If enabled, show quick-access numbers for the first ten candidates."
  :type '(choice (const :tag "off" nil)
                 (const :tag "on" t)))

(defcustom company-selection-wrap-around nil
  "If enabled, selecting item before first or after last wraps around."
  :type '(choice (const :tag "off" nil)
                 (const :tag "on" t)))

(defvar company-end-of-buffer-workaround t
  "Work around a visualization bug when completing at the end of the buffer.
The work-around consists of adding a newline.")

;;; mode ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-mode-map (make-sparse-keymap)
  "Keymap used by `company-mode'.")

(defvar company-active-map
  (let ((keymap (make-sparse-keymap)))
    (define-key keymap "\e\e\e" 'company-abort)
    (define-key keymap "\C-g" 'company-abort)
    (define-key keymap (kbd "M-n") 'company-select-next)
    (define-key keymap (kbd "M-p") 'company-select-previous)
    (define-key keymap (kbd "<down>") 'company-select-next-or-abort)
    (define-key keymap (kbd "<up>") 'company-select-previous-or-abort)
    (define-key keymap [down-mouse-1] 'ignore)
    (define-key keymap [down-mouse-3] 'ignore)
    (define-key keymap [mouse-1] 'company-complete-mouse)
    (define-key keymap [mouse-3] 'company-select-mouse)
    (define-key keymap [up-mouse-1] 'ignore)
    (define-key keymap [up-mouse-3] 'ignore)
    (define-key keymap [return] 'company-complete-selection)
    (define-key keymap (kbd "RET") 'company-complete-selection)
    (define-key keymap [tab] 'company-complete-common)
    (define-key keymap (kbd "TAB") 'company-complete-common)
    (define-key keymap (kbd "<f1>") 'company-show-doc-buffer)
    (define-key keymap "\C-w" 'company-show-location)
    (define-key keymap "\C-s" 'company-search-candidates)
    (define-key keymap "\C-\M-s" 'company-filter-candidates)
    (dotimes (i 10)
      (define-key keymap (vector (+ (aref (kbd "M-0") 0) i))
        `(lambda () (interactive) (company-complete-number ,i))))

    keymap)
  "Keymap that is enabled during an active completion.")

(defvar company--disabled-backends nil)

(defun company-init-backend (backend)
  (and (symbolp backend)
       (not (fboundp backend))
       (ignore-errors (require backend nil t)))

  (if (or (symbolp backend)
          (functionp backend))
      (condition-case err
          (progn
            (funcall backend 'init)
            (put backend 'company-init t))
        (error
         (put backend 'company-init 'failed)
         (unless (memq backend company--disabled-backends)
           (message "Company back-end '%s' could not be initialized:\n%s"
                    backend (error-message-string err)))
         (pushnew backend company--disabled-backends)
         nil))
    (mapc 'company-init-backend backend)))

(defvar company-default-lighter " company")

(defvar company-lighter company-default-lighter)
(make-variable-buffer-local 'company-lighter)

;;;###autoload
(define-minor-mode company-mode
  "\"complete anything\"; is an in-buffer completion framework.
Completion starts automatically, depending on the values
`company-idle-delay' and `company-minimum-prefix-length'.

Completion can be controlled with the commands:
`company-complete-common', `company-complete-selection', `company-complete',
`company-select-next', `company-select-previous'.  If these commands are
called before `company-idle-delay', completion will also start.

Completions can be searched with `company-search-candidates' or
`company-filter-candidates'.  These can be used while completion is
inactive, as well.

The completion data is retrieved using `company-backends' and displayed
using `company-frontends'.  If you want to start a specific back-end, call
it interactively or use `company-begin-backend'.

regular keymap (`company-mode-map'):

\\{company-mode-map}
keymap during active completions (`company-active-map'):

\\{company-active-map}"
  nil company-lighter company-mode-map
  (if company-mode
      (progn
        (add-hook 'pre-command-hook 'company-pre-command nil t)
        (add-hook 'post-command-hook 'company-post-command nil t)
        (mapc 'company-init-backend company-backends))
    (remove-hook 'pre-command-hook 'company-pre-command t)
    (remove-hook 'post-command-hook 'company-post-command t)
    (company-cancel)
    (kill-local-variable 'company-point)))

(defcustom company-global-modes t
  "Modes for which `company-mode' mode is turned on by `global-company-mode'.
If nil, means no modes.  If t, then all major modes have it turned on.
If a list, it should be a list of `major-mode' symbol names for which
`company-mode' should be automatically turned on.  The sense of the list is
negated if it begins with `not'.  For example:
 (c-mode c++-mode)
means that `company-mode' is turned on for buffers in C and C++ modes only.
 (not message-mode)
means that `company-mode' is always turned on except in `message-mode' buffers."
  :type '(choice (const :tag "none" nil)
                 (const :tag "all" t)
                 (set :menu-tag "mode specific" :tag "modes"
                      :value (not)
                      (const :tag "Except" not)
                      (repeat :inline t (symbol :tag "mode")))))

;;;###autoload
(define-globalized-minor-mode global-company-mode company-mode company-mode-on)

(defun company-mode-on ()
  (when (and (not (or noninteractive (eq (aref (buffer-name) 0) ?\s)))
             (cond ((eq company-global-modes t)
                    t)
                   ((eq (car-safe company-global-modes) 'not)
                    (not (memq major-mode (cdr company-global-modes))))
                   (t (memq major-mode company-global-modes))))
    (company-mode 1)))

(defsubst company-assert-enabled ()
  (unless company-mode
    (company-uninstall-map)
    (error "Company not enabled")))

;;; keymaps ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-my-keymap nil)
(make-variable-buffer-local 'company-my-keymap)

(defvar company-emulation-alist '((t . nil)))

(defsubst company-enable-overriding-keymap (keymap)
  (company-uninstall-map)
  (setq company-my-keymap keymap))

(defun company-ensure-emulation-alist ()
  (unless (eq 'company-emulation-alist (car emulation-mode-map-alists))
    (setq emulation-mode-map-alists
          (cons 'company-emulation-alist
                (delq 'company-emulation-alist emulation-mode-map-alists)))))

(defun company-install-map ()
  (unless (or (cdar company-emulation-alist)
              (null company-my-keymap))
    (setf (cdar company-emulation-alist) company-my-keymap)))

(defun company-uninstall-map ()
  (setf (cdar company-emulation-alist) nil))

;; Hack:
;; Emacs calculates the active keymaps before reading the event.  That means we
;; cannot change the keymap from a timer.  So we send a bogus command.
(defun company-ignore ()
  (interactive)
  (setq this-command last-command))

(global-set-key '[31415926] 'company-ignore)

(defun company-input-noop ()
  (push 31415926 unread-command-events))

(defun company--column (&optional pos)
  (save-excursion
    (when pos (goto-char pos))
    (save-restriction
      (+ (save-excursion
           (vertical-motion 0)
           (narrow-to-region (point) (point-max))
           (let ((prefix (get-text-property (point) 'line-prefix)))
             (if prefix (length prefix) 0)))
         (current-column)))))

(defun company--row (&optional pos)
  (save-excursion
    (when pos (goto-char pos))
    (count-screen-lines (window-start)
                        (progn (vertical-motion 0) (point)))))

;;; backends ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-backend nil)
(make-variable-buffer-local 'company-backend)

(defun company-grab (regexp &optional expression limit)
  (when (looking-back regexp limit)
    (or (match-string-no-properties (or expression 0)) "")))

(defun company-grab-line (regexp &optional expression)
  (company-grab regexp expression (point-at-bol)))

(defun company-grab-symbol ()
  (if (looking-at "\\_>")
      (buffer-substring (point) (save-excursion (skip-syntax-backward "w_")
                                                (point)))
    (unless (and (char-after) (memq (char-syntax (char-after)) '(?w ?_)))
      "")))

(defun company-grab-word ()
  (if (looking-at "\\>")
      (buffer-substring (point) (save-excursion (skip-syntax-backward "w")
                                                (point)))
    (unless (and (char-after) (eq (char-syntax (char-after)) ?w))
      "")))

(defun company-in-string-or-comment ()
  (let ((ppss (syntax-ppss)))
    (or (car (setq ppss (nthcdr 3 ppss)))
        (car (setq ppss (cdr ppss)))
        (nth 3 ppss))))

(if (fboundp 'locate-dominating-file)
    (defalias 'company-locate-dominating-file 'locate-dominating-file)
  (defun company-locate-dominating-file (file name)
    (catch 'root
      (let ((dir (file-name-directory file))
            (prev-dir nil))
        (while (not (equal dir prev-dir))
          (when (file-exists-p (expand-file-name name dir))
            (throw 'root dir))
          (setq prev-dir dir
                dir (file-name-directory (directory-file-name dir))))))))

(defun company-call-backend (&rest args)
  (if (functionp company-backend)
      (apply company-backend args)
    (apply 'company--multi-backend-adapter company-backend args)))

(defun company--multi-backend-adapter (backends command &rest args)
  (let ((backends (loop for b in backends
                        when (not (and (symbolp b)
                                       (eq 'failed (get b 'company-init))))
                        collect b)))
    (case command
      (candidates
       (loop for backend in backends
             when (equal (funcall backend 'prefix)
                         (car args))
             append (apply backend 'candidates args)))
      (sorted nil)
      (duplicates t)
      (otherwise
       (let (value)
         (dolist (backend backends)
           (when (setq value (apply backend command args))
             (return value))))))))

;;; completion mechanism ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-prefix nil)
(make-variable-buffer-local 'company-prefix)

(defvar company-candidates nil)
(make-variable-buffer-local 'company-candidates)

(defvar company-candidates-length nil)
(make-variable-buffer-local 'company-candidates-length)

(defvar company-candidates-cache nil)
(make-variable-buffer-local 'company-candidates-cache)

(defvar company-candidates-predicate nil)
(make-variable-buffer-local 'company-candidates-predicate)

(defvar company-common nil)
(make-variable-buffer-local 'company-common)

(defvar company-selection 0)
(make-variable-buffer-local 'company-selection)

(defvar company-selection-changed nil)
(make-variable-buffer-local 'company-selection-changed)

(defvar company--explicit-action nil
  "Non-nil, if explicit completion took place.")
(make-variable-buffer-local 'company--explicit-action)

(defvar company--auto-completion nil
  "Non-nil when current candidate is being inserted automatically.
Controlled by `company-auto-complete'.")

(defvar company--point-max nil)
(make-variable-buffer-local 'company--point-max)

(defvar company-point nil)
(make-variable-buffer-local 'company-point)

(defvar company-timer nil)

(defvar company-added-newline nil)
(make-variable-buffer-local 'company-added-newline)

(defsubst company-strip-prefix (str)
  (substring str (length company-prefix)))

(defun company--insert-candidate (candidate)
  ;; XXX: Return value we check here is subject to change.
  (set-text-properties 0 (length candidate) nil candidate)
  (if (eq (company-call-backend 'ignore-case) 'keep-prefix)
      (insert (company-strip-prefix candidate))
    (delete-region (- (point) (length company-prefix)) (point))
    (insert candidate)))

(defmacro company-with-candidate-inserted (candidate &rest body)
  "Evaluate BODY with CANDIDATE temporarily inserted.
This is a tool for back-ends that need candidates inserted before they
can retrieve meta-data for them."
  (declare (indent 1))
  `(let ((inhibit-modification-hooks t)
         (inhibit-point-motion-hooks t)
         (modified-p (buffer-modified-p)))
     (company--insert-candidate ,candidate)
     (unwind-protect
         (progn ,@body)
       (delete-region company-point (point)))))

(defun company-explicit-action-p ()
  "Return whether explicit completion action was taken by the user."
  (or company--explicit-action
      company-selection-changed))

(defun company-reformat (candidate)
  ;; company-ispell needs this, because the results are always lower-case
  ;; It's mory efficient to fix it only when they are displayed.
  ;; FIXME: Adopt the current text's capitalization instead?
  (if (eq (company-call-backend 'ignore-case) 'keep-prefix)
      (concat company-prefix (substring candidate (length company-prefix)))
    candidate))

(defun company--should-complete ()
  (and (not (or buffer-read-only overriding-terminal-local-map
                overriding-local-map))
       ;; Check if in the middle of entering a key combination.
       (or (equal (this-command-keys-vector) [])
           (not (keymapp (key-binding (this-command-keys-vector)))))
       (eq company-idle-delay t)
       (or (eq t company-begin-commands)
           (memq this-command company-begin-commands)
           (and (symbolp this-command) (get this-command 'company-begin)))
       (not (and transient-mark-mode mark-active))))

(defun company-call-frontends (command)
  (dolist (frontend company-frontends)
    (condition-case err
        (funcall frontend command)
      (error (error "Company: Front-end %s error \"%s\" on command %s"
                    frontend (error-message-string err) command)))))

(defun company-set-selection (selection &optional force-update)
  (setq selection
        (if company-selection-wrap-around
            (mod selection company-candidates-length)
          (max 0 (min (1- company-candidates-length) selection))))
  (when (or force-update (not (equal selection company-selection)))
    (setq company-selection selection
          company-selection-changed t)
    (company-call-frontends 'update)))

(defun company-apply-predicate (candidates predicate)
  (let (new)
    (dolist (c candidates)
      (when (funcall predicate c)
        (push c new)))
    (nreverse new)))

(defun company-update-candidates (candidates)
  (setq company-candidates-length (length candidates))
  (if (> company-selection 0)
      ;; Try to restore the selection
      (let ((selected (nth company-selection company-candidates)))
        (setq company-selection 0
              company-candidates candidates)
        (when selected
          (while (and candidates (string< (pop candidates) selected))
            (incf company-selection))
          (unless candidates
            ;; Make sure selection isn't out of bounds.
            (setq company-selection (min (1- company-candidates-length)
                                         company-selection)))))
    (setq company-selection 0
          company-candidates candidates))
  ;; Save in cache:
  (push (cons company-prefix company-candidates) company-candidates-cache)
  ;; Calculate common.
  (let ((completion-ignore-case (company-call-backend 'ignore-case)))
    ;; We want to support non-prefix completion, so filtering is the
    ;; responsibility of each respective backend, not ours.
    ;; On the other hand, we don't want to replace non-prefix input in
    ;; `company-complete-common'.
    (setq company-common
          (if (cdr company-candidates)
              (company--safe-candidate
               (try-completion company-prefix company-candidates))
            (car company-candidates)))))

(defun company--safe-candidate (str)
  (or (company-call-backend 'crop str)
      str))

(defun company-calculate-candidates (prefix)
  (let ((candidates (cdr (assoc prefix company-candidates-cache)))
        (ignore-case (company-call-backend 'ignore-case)))
    (or candidates
        (when company-candidates-cache
          (let ((len (length prefix))
                (completion-ignore-case ignore-case)
                prev)
            (dotimes (i (1+ len))
              (when (setq prev (cdr (assoc (substring prefix 0 (- len i))
                                           company-candidates-cache)))
                (setq candidates (all-completions prefix prev))
                (return t)))))
        ;; no cache match, call back-end
        (progn
          (setq candidates (company-call-backend 'candidates prefix))
          (when company-candidates-predicate
            (setq candidates
                  (company-apply-predicate candidates
                                           company-candidates-predicate)))
          (unless (company-call-backend 'sorted)
            (setq candidates (sort candidates 'string<)))
          (when (company-call-backend 'duplicates)
            ;; strip duplicates
            (let ((c2 candidates))
              (while c2
                (setcdr c2 (progn (while (equal (pop c2) (car c2)))
                                  c2)))))))
    (setq candidates (company--transform-candidates candidates))
    (when candidates
      (if (or (cdr candidates)
              (not (eq t (compare-strings (car candidates) nil nil
                                          prefix nil nil ignore-case))))
          (company--transform-candidates candidates)
        ;; Already completed and unique; don't start.
        t))))

(defun company--transform-candidates (candidates)
  (let ((c candidates))
    (dolist (tr company-transformers)
      (setq c (funcall tr c)))
    c))

(defun company-sort-by-occurrence (candidates)
  "Sort CANDIDATES according to their occurrences.
Searches for each in the currently visible part of the current buffer and
gives priority to the closest ones above point, then closest ones below
point. The rest of the list is appended unchanged."
  (let* (occurs
         (noccurs
          (delete-if
           (lambda (candidate)
             (when (or
                    (save-excursion
                      (and (zerop (forward-line -1))
                           (search-backward candidate (window-start) t)))
                    (save-excursion
                      (search-forward candidate (window-end) t)))
               (let ((beg (match-beginning 0))
                     (end (match-end 0)))
                 (when (save-excursion
                         (goto-char end)
                         (and (not (memq (get-text-property (point) 'face)
                                         '(font-lock-function-name-face
                                           font-lock-keyword-face)))
                              (let* ((prefix (company-call-backend 'prefix))
                                     (prefix (or (car-safe prefix) prefix)))
                                (and (stringp prefix)
                                     (= (length prefix) (- end beg))))))
                   (push (cons candidate (if (< beg (point))
                                             (- (point) end)
                                           (- beg (window-start))))
                         occurs)
                   t))))
           candidates)))
    (nconc
     (mapcar #'car (sort occurs (lambda (e1 e2) (< (cdr e1) (cdr e2)))))
     noccurs)))

(defun company-idle-begin (buf win tick pos)
  (and company-mode
       (eq buf (current-buffer))
       (eq win (selected-window))
       (eq tick (buffer-chars-modified-tick))
       (eq pos (point))
       (not company-candidates)
       (not (equal (point) company-point))
       (let ((company-idle-delay t)
             (company-begin-commands t))
         (company-begin)
         (when company-candidates
           (company-input-noop)
           (company-post-command)))))

(defun company-auto-begin ()
  (company-assert-enabled)
  (and company-mode
       (not company-candidates)
       (let ((company-idle-delay t)
             (company-minimum-prefix-length 0)
             (company-begin-commands t))
         (company-begin)))
  ;; Return non-nil if active.
  company-candidates)

(defun company-manual-begin ()
  (interactive)
  (setq company--explicit-action t)
  (unwind-protect
      (company-auto-begin)
    (unless company-candidates
      (setq company--explicit-action nil))))

(defun company-other-backend (&optional backward)
  (interactive (list current-prefix-arg))
  (company-assert-enabled)
  (if company-backend
      (let* ((after (cdr (member company-backend company-backends)))
             (before (cdr (member company-backend (reverse company-backends))))
             (next (if backward
                       (append before (reverse after))
                     (append after (reverse before)))))
        (company-cancel)
        (dolist (backend next)
          (when (ignore-errors (company-begin-backend backend))
            (return t))))
    (company-manual-begin))
  (unless company-candidates
    (error "No other back-end")))

(defun company-require-match-p ()
  (let ((backend-value (company-call-backend 'require-match)))
    (or (eq backend-value t)
        (and (not (eq backend-value 'never))
             (if (functionp company-require-match)
                 (funcall company-require-match)
               (eq company-require-match t))))))

(defun company-auto-complete-p (input)
  "Return non-nil, if input starts with punctuation or parentheses."
  (and (if (functionp company-auto-complete)
           (funcall company-auto-complete)
         company-auto-complete)
       (if (functionp company-auto-complete-chars)
           (funcall company-auto-complete-chars input)
         (if (consp company-auto-complete-chars)
             (memq (char-syntax (string-to-char input))
                   company-auto-complete-chars)
           (string-match (substring input 0 1) company-auto-complete-chars)))))

(defun company--incremental-p ()
  (and (> (point) company-point)
       (> (point-max) company--point-max)
       (not (eq this-command 'backward-delete-char-untabify))
       (equal (buffer-substring (- company-point (length company-prefix))
                                company-point)
              company-prefix)))

(defsubst company--string-incremental-p (old-prefix new-prefix)
  (and (> (length new-prefix) (length old-prefix))
       (equal old-prefix (substring new-prefix 0 (length old-prefix)))))

(defun company--continue-failed (new-prefix)
  (when (company--incremental-p)
    (let ((input (buffer-substring-no-properties (point) company-point)))
      (cond
       ((company-auto-complete-p input)
        ;; auto-complete
        (save-excursion
          (goto-char company-point)
          (let ((company--auto-completion t))
            (company-complete-selection))
          nil))
       ((and (company--string-incremental-p company-prefix new-prefix)
             (company-require-match-p))
        ;; wrong incremental input, but required match
        (delete-char (- (length input)))
        (ding)
        (message "Matching input is required")
        company-candidates)
       ((equal company-prefix (car company-candidates))
        ;; last input was actually success
        (company-cancel company-prefix)
        nil)))))

(defun company--good-prefix-p (prefix)
  (and (or (company-explicit-action-p)
           (unless (eq prefix 'stop)
             (or (eq (cdr-safe prefix) t)
                 (>= (or (cdr-safe prefix) (length prefix))
                     company-minimum-prefix-length))))
       (stringp (or (car-safe prefix) prefix))))

(defun company--continue ()
  (when (company-call-backend 'no-cache company-prefix)
    ;; Don't complete existing candidates, fetch new ones.
    (setq company-candidates-cache nil))
  (let* ((new-prefix (company-call-backend 'prefix))
         (c (when (and (company--good-prefix-p new-prefix)
                       (setq new-prefix (or (car-safe new-prefix) new-prefix))
                       (= (- (point) (length new-prefix))
                          (- company-point (length company-prefix))))
              (setq new-prefix (or (car-safe new-prefix) new-prefix))
              (company-calculate-candidates new-prefix))))
    (or (cond
         ((eq c t)
          ;; t means complete/unique.
          (company-cancel new-prefix)
          nil)
         ((consp c)
          ;; incremental match
          (setq company-prefix new-prefix)
          (company-update-candidates c)
          c)
         (t (company--continue-failed new-prefix)))
        (company-cancel))))

(defun company--begin-new ()
  (let (prefix c)
    (dolist (backend (if company-backend
                         ;; prefer manual override
                         (list company-backend)
                       company-backends))
      (setq prefix
            (if (or (symbolp backend)
                    (functionp backend))
                (when (or (not (symbolp backend))
                          (eq t (get backend 'company-init))
                          (unless (get backend 'company-init)
                            (company-init-backend backend)))
                  (funcall backend 'prefix))
              (company--multi-backend-adapter backend 'prefix)))
      (when prefix
        (when (company--good-prefix-p prefix)
          (setq prefix (or (car-safe prefix) prefix)
                company-backend backend
                c (company-calculate-candidates prefix))
          ;; t means complete/unique.  We don't start, so no hooks.
          (if (not (consp c))
              (when company--explicit-action
                (message "No completion found"))
            (setq company-prefix prefix)
            (when (symbolp backend)
              (setq company-lighter (concat " " (symbol-name backend))))
            (company-update-candidates c)
            (run-hook-with-args 'company-completion-started-hook
                                (company-explicit-action-p))
            (company-call-frontends 'show)))
        (return c)))))

(defun company-begin ()
  (or (and company-candidates (company--continue))
      (and (company--should-complete) (company--begin-new)))
  (when company-candidates
    (when (and company-end-of-buffer-workaround (eobp))
      (save-excursion (insert "\n"))
      (setq company-added-newline (buffer-chars-modified-tick)))
    (setq company-point (point)
          company--point-max (point-max))
    (company-ensure-emulation-alist)
    (company-enable-overriding-keymap company-active-map)
    (company-call-frontends 'update)))

(defun company-cancel (&optional result)
  (and company-added-newline
       (> (point-max) (point-min))
       (let ((tick (buffer-chars-modified-tick)))
         (delete-region (1- (point-max)) (point-max))
         (equal tick company-added-newline))
       ;; Only set unmodified when tick remained the same since insert.
       (set-buffer-modified-p nil))
  (when company-prefix
    (if (stringp result)
        (progn
          (company-call-backend 'pre-completion result)
          (run-hook-with-args 'company-completion-finished-hook result)
          (company-call-backend 'post-completion result))
      (run-hook-with-args 'company-completion-cancelled-hook result)))
  (setq company-added-newline nil
        company-backend nil
        company-prefix nil
        company-candidates nil
        company-candidates-length nil
        company-candidates-cache nil
        company-candidates-predicate nil
        company-common nil
        company-selection 0
        company-selection-changed nil
        company--explicit-action nil
        company-lighter company-default-lighter
        company--point-max nil
        company-point nil)
  (when company-timer
    (cancel-timer company-timer))
  (company-search-mode 0)
  (company-call-frontends 'hide)
  (company-enable-overriding-keymap nil))

(defun company-abort ()
  (interactive)
  (company-cancel t)
  ;; Don't start again, unless started manually.
  (setq company-point (point)))

(defun company-finish (result)
  (company--insert-candidate result)
  (company-cancel result)
  ;; Don't start again, unless started manually.
  (setq company-point (point)))

(defsubst company-keep (command)
  (and (symbolp command) (get command 'company-keep)))

(defun company-pre-command ()
  (unless (company-keep this-command)
    (condition-case err
        (when company-candidates
          (company-call-frontends 'pre-command))
      (error (message "Company: An error occurred in pre-command")
             (message "%s" (error-message-string err))
             (company-cancel))))
  (when company-timer
    (cancel-timer company-timer)
    (setq company-timer nil))
  (company-uninstall-map))

(defun company-post-command ()
  (unless (company-keep this-command)
    (condition-case err
        (progn
          (unless (equal (point) company-point)
            (company-begin))
          (if company-candidates
              (company-call-frontends 'post-command)
            (and (numberp company-idle-delay)
                 (or (eq t company-begin-commands)
                     (memq this-command company-begin-commands))
                 (setq company-timer
                       (run-with-timer company-idle-delay nil
                                       'company-idle-begin
                                       (current-buffer) (selected-window)
                                       (buffer-chars-modified-tick) (point))))))
      (error (message "Company: An error occurred in post-command")
             (message "%s" (error-message-string err))
             (company-cancel))))
  (company-install-map))

;;; search ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-search-string nil)
(make-variable-buffer-local 'company-search-string)

(defvar company-search-lighter " Search: \"\"")
(make-variable-buffer-local 'company-search-lighter)

(defvar company-search-old-map nil)
(make-variable-buffer-local 'company-search-old-map)

(defvar company-search-old-selection 0)
(make-variable-buffer-local 'company-search-old-selection)

(defun company-search (text lines)
  (let ((quoted (regexp-quote text))
        (i 0))
    (dolist (line lines)
      (when (string-match quoted line (length company-prefix))
        (return i))
      (incf i))))

(defun company-search-printing-char ()
  (interactive)
  (company-search-assert-enabled)
  (setq company-search-string
        (concat (or company-search-string "") (string last-command-event))
        company-search-lighter (concat " Search: \"" company-search-string
                                        "\""))
  (let ((pos (company-search company-search-string
                              (nthcdr company-selection company-candidates))))
    (if (null pos)
        (ding)
      (company-set-selection (+ company-selection pos) t))))

(defun company-search-repeat-forward ()
  "Repeat the incremental search in completion candidates forward."
  (interactive)
  (company-search-assert-enabled)
  (let ((pos (company-search company-search-string
                              (cdr (nthcdr company-selection
                                           company-candidates)))))
    (if (null pos)
        (ding)
      (company-set-selection (+ company-selection pos 1) t))))

(defun company-search-repeat-backward ()
  "Repeat the incremental search in completion candidates backwards."
  (interactive)
  (company-search-assert-enabled)
  (let ((pos (company-search company-search-string
                              (nthcdr (- company-candidates-length
                                         company-selection)
                                      (reverse company-candidates)))))
    (if (null pos)
        (ding)
      (company-set-selection (- company-selection pos 1) t))))

(defun company-create-match-predicate ()
  (setq company-candidates-predicate
        `(lambda (candidate)
           ,(if company-candidates-predicate
                `(and (string-match ,company-search-string candidate)
                      (funcall ,company-candidates-predicate
                               candidate))
              `(string-match ,company-search-string candidate))))
  (company-update-candidates
   (company-apply-predicate company-candidates company-candidates-predicate))
  ;; Invalidate cache.
  (setq company-candidates-cache (cons company-prefix company-candidates)))

(defun company-filter-printing-char ()
  (interactive)
  (company-search-assert-enabled)
  (company-search-printing-char)
  (company-create-match-predicate)
  (company-call-frontends 'update))

(defun company-search-kill-others ()
  "Limit the completion candidates to the ones matching the search string."
  (interactive)
  (company-search-assert-enabled)
  (company-create-match-predicate)
  (company-search-mode 0)
  (company-call-frontends 'update))

(defun company-search-abort ()
  "Abort searching the completion candidates."
  (interactive)
  (company-search-assert-enabled)
  (company-set-selection company-search-old-selection t)
  (company-search-mode 0))

(defun company-search-other-char ()
  (interactive)
  (company-search-assert-enabled)
  (company-search-mode 0)
  (company--unread-last-input))

(defvar company-search-map
  (let ((i 0)
        (keymap (make-keymap)))
    (if (fboundp 'max-char)
        (set-char-table-range (nth 1 keymap) (cons #x100 (max-char))
                              'company-search-printing-char)
      (with-no-warnings
        ;; obsolete in Emacs 23
        (let ((l (generic-character-list))
              (table (nth 1 keymap)))
          (while l
            (set-char-table-default table (car l) 'company-search-printing-char)
            (setq l (cdr l))))))
    (define-key keymap [t] 'company-search-other-char)
    (while (< i ?\s)
      (define-key keymap (make-string 1 i) 'company-search-other-char)
      (incf i))
    (while (< i 256)
      (define-key keymap (vector i) 'company-search-printing-char)
      (incf i))
    (let ((meta-map (make-sparse-keymap)))
      (define-key keymap (char-to-string meta-prefix-char) meta-map)
      (define-key keymap [escape] meta-map))
    (define-key keymap (vector meta-prefix-char t) 'company-search-other-char)
    (define-key keymap "\e\e\e" 'company-search-other-char)
    (define-key keymap  [escape escape escape] 'company-search-other-char)

    (define-key keymap "\C-g" 'company-search-abort)
    (define-key keymap "\C-s" 'company-search-repeat-forward)
    (define-key keymap "\C-r" 'company-search-repeat-backward)
    (define-key keymap "\C-o" 'company-search-kill-others)
    keymap)
  "Keymap used for incrementally searching the completion candidates.")

(define-minor-mode company-search-mode
  "Search mode for completion candidates.
Don't start this directly, use `company-search-candidates' or
`company-filter-candidates'."
  nil company-search-lighter nil
  (if company-search-mode
      (if (company-manual-begin)
          (progn
            (setq company-search-old-selection company-selection)
            (company-call-frontends 'update))
        (setq company-search-mode nil))
    (kill-local-variable 'company-search-string)
    (kill-local-variable 'company-search-lighter)
    (kill-local-variable 'company-search-old-selection)
    (company-enable-overriding-keymap company-active-map)))

(defun company-search-assert-enabled ()
  (company-assert-enabled)
  (unless company-search-mode
    (company-uninstall-map)
    (error "Company not in search mode")))

(defun company-search-candidates ()
  "Start searching the completion candidates incrementally.

\\<company-search-map>Search can be controlled with the commands:
- `company-search-repeat-forward' (\\[company-search-repeat-forward])
- `company-search-repeat-backward' (\\[company-search-repeat-backward])
- `company-search-abort' (\\[company-search-abort])

Regular characters are appended to the search string.

The command `company-search-kill-others' (\\[company-search-kill-others])
uses the search string to limit the completion candidates."
  (interactive)
  (company-search-mode 1)
  (company-enable-overriding-keymap company-search-map))

(defvar company-filter-map
  (let ((keymap (make-keymap)))
    (define-key keymap [remap company-search-printing-char]
      'company-filter-printing-char)
    (set-keymap-parent keymap company-search-map)
    keymap)
  "Keymap used for incrementally searching the completion candidates.")

(defun company-filter-candidates ()
  "Start filtering the completion candidates incrementally.
This works the same way as `company-search-candidates' immediately
followed by `company-search-kill-others' after each input."
  (interactive)
  (company-search-mode 1)
  (company-enable-overriding-keymap company-filter-map))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun company-select-next ()
  "Select the next candidate in the list."
  (interactive)
  (when (company-manual-begin)
    (company-set-selection (1+ company-selection))))

(defun company-select-previous ()
  "Select the previous candidate in the list."
  (interactive)
  (when (company-manual-begin)
    (company-set-selection (1- company-selection))))

(defun company-select-next-or-abort ()
  "Select the next candidate if more than one, else abort
and invoke the normal binding."
  (interactive)
  (if (> company-candidates-length 1)
      (company-select-next)
    (company-abort)
    (company--unread-last-input)))

(defun company-select-previous-or-abort ()
  "Select the previous candidate if more than one, else abort
and invoke the normal binding."
  (interactive)
  (if (> company-candidates-length 1)
      (company-select-previous)
    (company-abort)
    (company--unread-last-input)))

(defvar company-pseudo-tooltip-overlay)

(defvar company-tooltip-offset)

(defun company--inside-tooltip-p (event-col-row row height)
  (let* ((ovl company-pseudo-tooltip-overlay)
         (column (overlay-get ovl 'company-column))
         (width (overlay-get ovl 'company-width))
         (evt-col (car event-col-row))
         (evt-row (cdr event-col-row)))
    (and (>= evt-col column)
         (< evt-col (+ column width))
         (if (> height 0)
             (and (> evt-row row)
                  (<= evt-row (+ row height) ))
           (and (< evt-row row)
                (>= evt-row (+ row height)))))))

(defun company--event-col-row (event)
  (let* ((col-row (posn-actual-col-row (event-start event)))
         (col (car col-row))
         (row (cdr col-row)))
    (incf col (window-hscroll))
    (and header-line-format
         (version< "24" emacs-version)
         (decf row))
    (cons col row)))

(defun company-select-mouse (event)
  "Select the candidate picked by the mouse."
  (interactive "e")
  (let ((event-col-row (company--event-col-row event))
        (ovl-row (company--row))
        (ovl-height (and company-pseudo-tooltip-overlay
                         (min (overlay-get company-pseudo-tooltip-overlay
                                           'company-height)
                              company-candidates-length))))
    (if (and ovl-height
             (company--inside-tooltip-p event-col-row ovl-row ovl-height))
        (progn
          (company-set-selection (+ (cdr event-col-row)
                                    (1- company-tooltip-offset)
                                    (if (and (eq company-tooltip-offset-display 'lines)
                                             (not (zerop company-tooltip-offset)))
                                        -1 0)
                                    (- ovl-row)
                                    (if (< ovl-height 0)
                                        (- 1 ovl-height)
                                      0)))
          t)
      (company-abort)
      (company--unread-last-input)
      nil)))

(defun company-complete-mouse (event)
  "Insert the candidate picked by the mouse."
  (interactive "e")
  (when (company-select-mouse event)
    (company-complete-selection)))

(defun company-complete-selection ()
  "Insert the selected candidate."
  (interactive)
  (when (company-manual-begin)
    (let ((result (nth company-selection company-candidates)))
      (when company--auto-completion
        (setq result (company--safe-candidate result)))
      (company-finish result))))

(defun company-complete-common ()
  "Insert the common part of all candidates."
  (interactive)
  (when (company-manual-begin)
    (if (and (not (cdr company-candidates))
             (equal company-common (car company-candidates)))
        (company-complete-selection)
      (when company-common
        (company--insert-candidate company-common)))))

(defun company-complete ()
  "Insert the common part of all candidates or the current selection.
The first time this is called, the common part is inserted, the second
time, or when the selection has been changed, the selected candidate is
inserted."
  (interactive)
  (when (company-manual-begin)
    (if (or company-selection-changed
            (eq last-command 'company-complete-common))
        (call-interactively 'company-complete-selection)
      (call-interactively 'company-complete-common)
      (setq this-command 'company-complete-common))))

(defun company-complete-number (n)
  "Insert the Nth candidate.
To show the number next to the candidates in some back-ends, enable
`company-show-numbers'."
  (when (company-manual-begin)
    (and (< n 1) (> n company-candidates-length)
         (error "No candidate number %d" n))
    (decf n)
    (company-finish (nth n company-candidates))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defconst company-space-strings-limit 100)

(defconst company-space-strings
  (let (lst)
    (dotimes (i company-space-strings-limit)
      (push (make-string (- company-space-strings-limit 1 i) ?\  ) lst))
    (apply 'vector lst)))

(defun company-space-string (len)
  (if (< len company-space-strings-limit)
      (aref company-space-strings len)
    (make-string len ?\ )))

(defun company-safe-substring (str from &optional to)
  (if (> from (string-width str))
      ""
    (with-temp-buffer
      (insert str)
      (move-to-column from)
      (let ((beg (point)))
        (if to
            (progn
              (move-to-column to)
              (concat (buffer-substring beg (point))
                      (let ((padding (- to (current-column))))
                        (when (> padding 0)
                          (company-space-string padding)))))
          (buffer-substring beg (point-max)))))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-last-metadata nil)
(make-variable-buffer-local 'company-last-metadata)

(defun company-fetch-metadata ()
  (let ((selected (nth company-selection company-candidates)))
    (unless (equal selected (car company-last-metadata))
      (setq company-last-metadata
            (cons selected (company-call-backend 'meta selected))))
    (cdr company-last-metadata)))

(defun company-doc-buffer (&optional string)
  (with-current-buffer (get-buffer-create "*company-documentation*")
    (erase-buffer)
    (when string
      (save-excursion
        (insert string)))
    (current-buffer)))

(defvar company--electric-commands
  '(scroll-other-window scroll-other-window-down)
  "List of Commands that won't break out of electric commands.")

(defmacro company--electric-do (&rest body)
  (declare (indent 0) (debug t))
  `(when (company-manual-begin)
     (save-window-excursion
       (let ((height (window-height))
             (row (company--row))
             cmd)
         ,@body
         (and (< (window-height) height)
              (< (- (window-height) row 2) company-tooltip-limit)
              (recenter (- (window-height) row 2)))
         (while (memq (setq cmd (key-binding (vector (list (read-event)))))
                      company--electric-commands)
           (call-interactively cmd))
         (company--unread-last-input)))))

(defun company--unread-last-input ()
  (when last-input-event
    (clear-this-command-keys t)
    (setq unread-command-events (list last-input-event))))

(defun company-show-doc-buffer ()
  "Temporarily show the documentation buffer for the selection."
  (interactive)
  (company--electric-do
    (let* ((selected (nth company-selection company-candidates))
           (doc-buffer (or (company-call-backend 'doc-buffer selected)
                           (error "No documentation available"))))
      (with-current-buffer doc-buffer
        (goto-char (point-min)))
      (display-buffer doc-buffer t))))
(put 'company-show-doc-buffer 'company-keep t)

(defun company-show-location ()
  "Temporarily display a buffer showing the selected candidate in context."
  (interactive)
  (company--electric-do
    (let* ((selected (nth company-selection company-candidates))
           (location (company-call-backend 'location selected))
           (pos (or (cdr location) (error "No location available")))
           (buffer (or (and (bufferp (car location)) (car location))
                       (find-file-noselect (car location) t))))
      (with-selected-window (display-buffer buffer t)
        (save-restriction
          (widen)
          (if (bufferp (car location))
              (goto-char pos)
            (goto-char (point-min))
            (forward-line (1- pos))))
        (set-window-start nil (point))))))
(put 'company-show-location 'company-keep t)

;;; package functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-callback nil)
(make-variable-buffer-local 'company-callback)

(defvar company-begin-with-marker nil)
(make-variable-buffer-local 'company-begin-with-marker)

(defun company-remove-callback (&optional ignored)
  (remove-hook 'company-completion-finished-hook company-callback t)
  (remove-hook 'company-completion-cancelled-hook 'company-remove-callback t)
  (remove-hook 'company-completion-finished-hook 'company-remove-callback t)
  (when company-begin-with-marker
    (set-marker company-begin-with-marker nil)))

(defun company-begin-backend (backend &optional callback)
  "Start a completion at point using BACKEND."
  (interactive (let ((val (completing-read "Company back-end: "
                                           obarray
                                           'functionp nil "company-")))
                 (when val
                   (list (intern val)))))
  (when (setq company-callback callback)
    (add-hook 'company-completion-finished-hook company-callback nil t))
  (add-hook 'company-completion-cancelled-hook 'company-remove-callback nil t)
  (add-hook 'company-completion-finished-hook 'company-remove-callback nil t)
  (setq company-backend backend)
  ;; Return non-nil if active.
  (or (company-manual-begin)
      (progn
        (setq company-backend nil)
        (error "Cannot complete at point"))))

(defun company-begin-with (candidates
                           &optional prefix-length require-match callback)
  "Start a completion at point.
CANDIDATES is the list of candidates to use and PREFIX-LENGTH is the length
of the prefix that already is in the buffer before point.
It defaults to 0.

CALLBACK is a function called with the selected result if the user
successfully completes the input.

Example: \(company-begin-with '\(\"foo\" \"foobar\" \"foobarbaz\"\)\)"
  ;; FIXME: When Emacs 23 is no longer a concern, replace
  ;; `company-begin-with-marker' with a lexical variable; use a lexical closure.
  (setq company-begin-with-marker (copy-marker (point) t))
  (company-begin-backend
   `(lambda (command &optional arg &rest ignored)
      (cond
       ((eq command 'prefix)
        (when (equal (point) (marker-position company-begin-with-marker))
          (buffer-substring ,(- (point) (or prefix-length 0)) (point))))
       ((eq command 'candidates)
        (all-completions arg ',candidates))
       ((eq command 'require-match)
        ,require-match)))
   callback))

;;; pseudo-tooltip ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-pseudo-tooltip-overlay nil)
(make-variable-buffer-local 'company-pseudo-tooltip-overlay)

(defvar company-tooltip-offset 0)
(make-variable-buffer-local 'company-tooltip-offset)

(defun company-tooltip--lines-update-offset (selection num-lines limit)
  (decf limit 2)
  (setq company-tooltip-offset
        (max (min selection company-tooltip-offset)
             (- selection -1 limit)))

  (when (<= company-tooltip-offset 1)
    (incf limit)
    (setq company-tooltip-offset 0))

  (when (>= company-tooltip-offset (- num-lines limit 1))
    (incf limit)
    (when (= selection (1- num-lines))
      (decf company-tooltip-offset)
      (when (<= company-tooltip-offset 1)
        (setq company-tooltip-offset 0)
        (incf limit))))

  limit)

(defun company-tooltip--simple-update-offset (selection num-lines limit)
  (setq company-tooltip-offset
        (if (< selection company-tooltip-offset)
            selection
          (max company-tooltip-offset
               (- selection limit -1)))))

;;; propertize

(defsubst company-round-tab (arg)
  (* (/ (+ arg tab-width) tab-width) tab-width))

(defun company-plainify (str)
  (let ((prefix (get-text-property 0 'line-prefix str)))
    (when prefix ; Keep the original value unmodified, for no special reason.
      (setq str (concat prefix str))
      (remove-text-properties 0 (length str) '(line-prefix) str)))
  (let* ((pieces (split-string str "\t"))
         (copy pieces))
    (while (cdr copy)
      (setcar copy (company-safe-substring
                    (car copy) 0 (company-round-tab (string-width (car copy)))))
      (pop copy))
    (apply 'concat pieces)))

(defun company--highlight-common (line properties)
  ;; XXX: Subject to change.
  (let ((common (or (company-call-backend 'common-part line)
                    (length company-common))))
    (add-text-properties 0 common properties line)))

(defun company-fill-propertize (line width selected)
  (let* ((margin company-tooltip-margin)
         (common (+ (or (company-call-backend 'common-part line)
                        (length company-common)) margin)))
    (setq line (concat (company-space-string company-tooltip-margin)
                       (company-safe-substring
                        line 0 (+ width company-tooltip-margin)))
          width (+ width (* 2 margin)))

    (add-text-properties 0 width '(face company-tooltip
                                   mouse-face company-tooltip-mouse)
                         line)
    (add-text-properties margin common
                         '(face company-tooltip-common
                           mouse-face company-tooltip-mouse)
                         line)
    (when selected
      (if (and company-search-string
               (string-match (regexp-quote company-search-string) line
                             (length company-prefix)))
          (progn
            (add-text-properties (match-beginning 0) (match-end 0)
                                 '(face company-tooltip-selection)
                                 line)
            (when (< (match-beginning 0) common)
              (add-text-properties (match-beginning 0) common
                                   '(face company-tooltip-common-selection)
                                   line)))
        (add-text-properties 0 width '(face company-tooltip-selection
                                       mouse-face company-tooltip-selection)
                             line)
        (add-text-properties margin common
                             '(face company-tooltip-common-selection
                               mouse-face company-tooltip-selection)
                             line))))
  line)

;;; replace

(defun company-buffer-lines (beg end)
  (goto-char beg)
  (let (lines)
    (while (and (= 1 (vertical-motion 1))
                (<= (point) end))
      (let ((bound (min end (1- (point)))))
        ;; A visual line can contain several physical lines (e.g. with outline's
        ;; folding overlay).  Take only the first one.
        (push (buffer-substring beg
                                (save-excursion
                                  (goto-char beg)
                                  (re-search-forward "$" bound 'move)
                                  (point)))
              lines))
      (setq beg (point)))
    (unless (eq beg end)
      (push (buffer-substring beg end) lines))
    (nreverse lines)))

(defun company-modify-line (old new offset)
  (concat (company-safe-substring old 0 offset)
          new
          (company-safe-substring old (+ offset (length new)))))

(defsubst company--length-limit (lst limit)
  (if (nthcdr limit lst)
      limit
    (length lst)))

(defun company--replacement-string (lines old column nl &optional align-top)
  (decf column company-tooltip-margin)

  (let ((width (length (car lines)))
        (remaining-cols (- (+ (company--window-width) (window-hscroll))
                           column)))
    (when (> width remaining-cols)
      (decf column (- width remaining-cols))))

  (let ((offset (and (< column 0) (- column)))
        new)
    (when offset
      (setq column 0))
    (when align-top
      ;; untouched lines first
      (dotimes (_ (- (length old) (length lines)))
        (push (pop old) new)))
    ;; length into old lines.
    (while old
      (push (company-modify-line (pop old)
                                 (company--offset-line (pop lines) offset)
                                 column) new))
    ;; Append whole new lines.
    (while lines
      (push (concat (company-space-string column)
                    (company--offset-line (pop lines) offset))
            new))

    (let ((str (concat (when nl "\n")
                       (mapconcat 'identity (nreverse new) "\n")
                       "\n")))
      (font-lock-append-text-property 0 (length str) 'face 'default str)
      str)))

(defun company--offset-line (line offset)
  (if (and offset line)
      (substring line offset)
    line))

(defun company--create-lines (selection limit)

  (let ((len company-candidates-length)
        (numbered 99999)
        (window-width (company--window-width))
        lines
        width
        lines-copy
        previous
        remainder
        scrollbar-bounds
        new)

    ;; Maybe clear old offset.
    (when (<= len (+ company-tooltip-offset limit))
      (setq company-tooltip-offset 0))

    ;; Scroll to offset.
    (if (eq company-tooltip-offset-display 'lines)
        (setq limit (company-tooltip--lines-update-offset selection len limit))
      (company-tooltip--simple-update-offset selection len limit))

    (cond
     ((eq company-tooltip-offset-display 'scrollbar)
      (setq scrollbar-bounds (company--scrollbar-bounds company-tooltip-offset
                                                        limit len)))
     ((eq company-tooltip-offset-display 'lines)
      (when (> company-tooltip-offset 0)
        (setq previous (format "...(%d)" company-tooltip-offset)))
      (setq remainder (- len limit company-tooltip-offset)
            remainder (when (> remainder 0)
                        (setq remainder (format "...(%d)" remainder))))))

    (decf selection company-tooltip-offset)
    (setq width (max (length previous) (length remainder))
          lines (nthcdr company-tooltip-offset company-candidates)
          len (min limit len)
          lines-copy lines)

    (decf window-width (* 2 company-tooltip-margin))
    (when scrollbar-bounds (decf window-width))

    (dotimes (_ len)
      (setq width (max (length (pop lines-copy)) width)))
    (setq width (min window-width
                     (if (and company-show-numbers
                              (< company-tooltip-offset 10))
                         (+ 2 width)
                       width)))
    (setq lines-copy lines)

    ;; number can make tooltip too long
    (when company-show-numbers
      (setq numbered company-tooltip-offset))

    (when previous
      (push (company--scrollpos-line previous width) new))

    (dotimes (i len)
      (let ((line (company-fill-propertize
                   (if (>= numbered 10)
                       (company-reformat (pop lines))
                     (incf numbered)
                     (format "%s %d"
                             (company-safe-substring
                              (company-reformat (pop lines)) 0 (- width 2))
                             (mod numbered 10)))
                   width (equal i selection))))
        (push (if scrollbar-bounds
                  (company--scrollbarize line i scrollbar-bounds)
                line)
              new)))

    (when remainder
      (push (company--scrollpos-line remainder width) new))

    (setq lines (nreverse new))))

(defun company--scrollbar-bounds (offset limit length)
  (when (> length limit)
    (let* ((size (ceiling (* limit (float limit)) length))
           (lower (floor (* limit (float offset)) length))
           (upper (+ lower size -1)))
      (cons lower upper))))

(defun company--scrollbarize (line i bounds)
  (concat line
          (propertize " " 'face
                      (if (and (>= i (car bounds)) (<= i (cdr bounds)))
                          'company-scrollbar-fg
                        'company-scrollbar-bg))))

(defun company--scrollpos-line (text width)
  (propertize (concat (company-space-string company-tooltip-margin)
                      (company-safe-substring text 0 width)
                      (company-space-string company-tooltip-margin))
   'face 'company-tooltip))

;; show

(defsubst company--window-inner-height ()
  (let ((edges (window-inside-edges)))
    (- (nth 3 edges) (nth 1 edges))))

(defsubst company--window-width ()
  (- (window-width)
     (cond
      ((display-graphic-p) 0)
      ;; Account for the line continuation column.
      ((version< "24.3.1" emacs-version) 1)
      ;; Emacs 24.3 and earlier included margins
      ;; in window-width when in TTY.
      (t (1+ (let ((margins (window-margins)))
               (+ (or (car margins) 0)
                  (or (cdr margins) 0))))))))

(defun company--pseudo-tooltip-height ()
  "Calculate the appropriate tooltip height.
Returns a negative number if the tooltip should be displayed above point."
  (let* ((lines (company--row))
         (below (- (company--window-inner-height) 1 lines)))
    (if (and (< below (min company-tooltip-minimum company-candidates-length))
             (> lines below))
        (- (max 3 (min company-tooltip-limit lines)))
      (max 3 (min company-tooltip-limit below)))))

(defun company-pseudo-tooltip-show (row column selection)
  (company-pseudo-tooltip-hide)
  (save-excursion

    (let* ((height (company--pseudo-tooltip-height))
           above)

      (when (< height 0)
        (setq row (+ row height -1)
              above t))

      (let* ((nl (< (move-to-window-line row) row))
             (beg (point))
             (end (save-excursion
                    (move-to-window-line (+ row (abs height)))
                    (point)))
             (ov (make-overlay beg end))
             (args (list (mapcar 'company-plainify
                                 (company-buffer-lines beg end))
                         column nl above)))

        (setq company-pseudo-tooltip-overlay ov)
        (overlay-put ov 'company-replacement-args args)

        (let ((lines (company--create-lines selection (abs height))))
          (overlay-put ov 'company-after
                       (apply 'company--replacement-string lines args))
          (overlay-put ov 'company-width (string-width (car lines))))

        (overlay-put ov 'company-column column)
        (overlay-put ov 'company-height height)))))

(defun company-pseudo-tooltip-show-at-point (pos)
  (let ((row (company--row pos))
        (col (company--column pos)))
    (company-pseudo-tooltip-show (1+ row) col company-selection)))

(defun company-pseudo-tooltip-edit (selection)
  (let ((height (overlay-get company-pseudo-tooltip-overlay 'company-height)))
    (overlay-put company-pseudo-tooltip-overlay 'company-after
                 (apply 'company--replacement-string
                        (company--create-lines selection (abs height))
                        (overlay-get company-pseudo-tooltip-overlay
                                     'company-replacement-args)))))

(defun company-pseudo-tooltip-hide ()
  (when company-pseudo-tooltip-overlay
    (delete-overlay company-pseudo-tooltip-overlay)
    (setq company-pseudo-tooltip-overlay nil)))

(defun company-pseudo-tooltip-hide-temporarily ()
  (when (overlayp company-pseudo-tooltip-overlay)
    (overlay-put company-pseudo-tooltip-overlay 'invisible nil)
    (overlay-put company-pseudo-tooltip-overlay 'line-prefix nil)
    (overlay-put company-pseudo-tooltip-overlay 'after-string nil)))

(defun company-pseudo-tooltip-unhide ()
  (when company-pseudo-tooltip-overlay
    (overlay-put company-pseudo-tooltip-overlay 'invisible t)
    ;; Beat outline's folding overlays, at least.
    (overlay-put company-pseudo-tooltip-overlay 'priority 1)
    ;; No (extra) prefix for the first line.
    (overlay-put company-pseudo-tooltip-overlay 'line-prefix "")
    (overlay-put company-pseudo-tooltip-overlay 'after-string
                 (overlay-get company-pseudo-tooltip-overlay 'company-after))
    (overlay-put company-pseudo-tooltip-overlay 'window (selected-window))))

(defun company-pseudo-tooltip-guard ()
  (buffer-substring-no-properties
   (point) (overlay-start company-pseudo-tooltip-overlay)))

(defun company-pseudo-tooltip-frontend (command)
  "`company-mode' front-end similar to a tooltip but based on overlays."
  (case command
    (pre-command (company-pseudo-tooltip-hide-temporarily))
    (post-command
     (let ((old-height (if (overlayp company-pseudo-tooltip-overlay)
                           (overlay-get company-pseudo-tooltip-overlay
                                        'company-height)
                         0))
           (new-height (company--pseudo-tooltip-height)))
       (unless (and (>= (* old-height new-height) 0)
                    (>= (abs old-height) (abs new-height))
                    (equal (company-pseudo-tooltip-guard)
                           (overlay-get company-pseudo-tooltip-overlay
                                        'company-guard)))
         ;; Redraw needed.
         (company-pseudo-tooltip-show-at-point (- (point)
                                                  (length company-prefix)))
         (overlay-put company-pseudo-tooltip-overlay
                      'company-guard (company-pseudo-tooltip-guard))))
     (company-pseudo-tooltip-unhide))
    (hide (company-pseudo-tooltip-hide)
          (setq company-tooltip-offset 0))
    (update (when (overlayp company-pseudo-tooltip-overlay)
              (company-pseudo-tooltip-edit company-selection)))))

(defun company-pseudo-tooltip-unless-just-one-frontend (command)
  "`company-pseudo-tooltip-frontend', but not shown for single candidates."
  (unless (and (eq command 'post-command)
               (company--show-inline-p))
    (company-pseudo-tooltip-frontend command)))

;;; overlay ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-preview-overlay nil)
(make-variable-buffer-local 'company-preview-overlay)

(defun company-preview-show-at-point (pos)
  (company-preview-hide)

  (setq company-preview-overlay (make-overlay pos pos))

  (let ((completion(nth company-selection company-candidates)))
    (setq completion (propertize completion 'face 'company-preview))
    (add-text-properties 0 (length company-common)
                         '(face company-preview-common) completion)

    ;; Add search string
    (and company-search-string
         (string-match (regexp-quote company-search-string) completion)
         (add-text-properties (match-beginning 0)
                              (match-end 0)
                              '(face company-preview-search)
                              completion))

    (setq completion (company-strip-prefix completion))

    (and (equal pos (point))
         (not (equal completion ""))
         (add-text-properties 0 1 '(cursor t) completion))

    (overlay-put company-preview-overlay 'after-string completion)
    (overlay-put company-preview-overlay 'window (selected-window))))

(defun company-preview-hide ()
  (when company-preview-overlay
    (delete-overlay company-preview-overlay)
    (setq company-preview-overlay nil)))

(defun company-preview-frontend (command)
  "`company-mode' front-end showing the selection as if it had been inserted."
  (case command
    (pre-command (company-preview-hide))
    (post-command (company-preview-show-at-point (point)))
    (hide (company-preview-hide))))

(defun company-preview-if-just-one-frontend (command)
  "`company-preview-frontend', but only shown for single candidates."
  (when (or (not (eq command 'post-command))
            (company--show-inline-p))
    (company-preview-frontend command)))

(defun company--show-inline-p ()
  (and (not (cdr company-candidates))
       company-common
       (string-prefix-p company-prefix company-common
                        (company-call-backend 'ignore-case))))

;;; echo ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar company-echo-last-msg nil)
(make-variable-buffer-local 'company-echo-last-msg)

(defvar company-echo-timer nil)

(defvar company-echo-delay .01)

(defun company-echo-show (&optional getter)
  (when getter
    (setq company-echo-last-msg (funcall getter)))
  (let ((message-log-max nil))
    (if company-echo-last-msg
        (message "%s" company-echo-last-msg)
      (message ""))))

(defun company-echo-show-soon (&optional getter)
  (when company-echo-timer
    (cancel-timer company-echo-timer))
  (setq company-echo-timer (run-with-timer 0 nil 'company-echo-show getter)))

(defsubst company-echo-show-when-idle (&optional getter)
  (when (sit-for company-echo-delay)
    (company-echo-show getter)))

(defun company-echo-format ()

  (let ((limit (window-width (minibuffer-window)))
        (len -1)
        ;; Roll to selection.
        (candidates (nthcdr company-selection company-candidates))
        (i (if company-show-numbers company-selection 99999))
        comp msg)

    (while candidates
      (setq comp (company-reformat (pop candidates))
            len (+ len 1 (length comp)))
      (if (< i 10)
          ;; Add number.
          (progn
            (setq comp (propertize (format "%d: %s" i comp)
                                   'face 'company-echo))
            (incf len 3)
            (incf i)
            (add-text-properties 3 (+ 3 (length company-common))
                                 '(face company-echo-common) comp))
        (setq comp (propertize comp 'face 'company-echo))
        (add-text-properties 0 (length company-common)
                             '(face company-echo-common) comp))
      (if (>= len limit)
          (setq candidates nil)
        (push comp msg)))

    (mapconcat 'identity (nreverse msg) " ")))

(defun company-echo-strip-common-format ()

  (let ((limit (window-width (minibuffer-window)))
        (len (+ (length company-prefix) 2))
        ;; Roll to selection.
        (candidates (nthcdr company-selection company-candidates))
        (i (if company-show-numbers company-selection 99999))
        msg comp)

    (while candidates
      (setq comp (company-strip-prefix (pop candidates))
            len (+ len 2 (length comp)))
      (when (< i 10)
        ;; Add number.
        (setq comp (format "%s (%d)" comp i))
        (incf len 4)
        (incf i))
      (if (>= len limit)
          (setq candidates nil)
        (push (propertize comp 'face 'company-echo) msg)))

    (concat (propertize company-prefix 'face 'company-echo-common) "{"
            (mapconcat 'identity (nreverse msg) ", ")
            "}")))

(defun company-echo-hide ()
  (unless (equal company-echo-last-msg "")
    (setq company-echo-last-msg "")
    (company-echo-show)))

(defun company-echo-frontend (command)
  "`company-mode' front-end showing the candidates in the echo area."
  (case command
    (post-command (company-echo-show-soon 'company-echo-format))
    (hide (company-echo-hide))))

(defun company-echo-strip-common-frontend (command)
  "`company-mode' front-end showing the candidates in the echo area."
  (case command
    (post-command (company-echo-show-soon 'company-echo-strip-common-format))
    (hide (company-echo-hide))))

(defun company-echo-metadata-frontend (command)
  "`company-mode' front-end showing the documentation in the echo area."
  (case command
    (post-command (company-echo-show-when-idle 'company-fetch-metadata))
    (hide (company-echo-hide))))

(provide 'company)
;;; company.el ends here