To install this package, run in Emacs:
M-x package-install RET corfu RET
Corfu enhances completion at point with a small completion popup. The current
candidates are shown in a popup below or above the point. Corfu is the
completion-in-region counterpart of the Vertico minibuffer UI.
Corfu is a small package, which relies on the Emacs completion facilities and
concentrates on providing a polished completion UI. Completions are either
provided by commands like
dabbrev-completion or by pluggable backends
completion-at-point-functions, Capfs). Most programming language major modes
implement a Capf. Furthermore the language server packages, Eglot and Lsp-mode,
use Capfs which talk to the LSP server to retrieve the completions. Corfu does
not include its own completion backends. The Emacs built-in Capfs and the Capfs
provided by other programming language packages are usually sufficient. A few
additional Capfs and completion utilities are provided by the Cape package.
NOTE: Corfu uses child frames to show the popup and falls back to the default
setting of the
completion-in-region-function on non-graphical displays. If you
want to use Corfu in the terminal, install the package corfu-terminal, which
provides an alternative overlay-based display.
TABat any time.
TABand selected with
Corfu is available from GNU ELPA, such that it can be installed directly via
package-install. After installation, the global minor mode can be enabled with
M-x global-corfu-mode. In order to configure Corfu and other packages in your
init.el, you may want to use
Corfu is highly flexible and customizable via
corfu-* customization variables,
such that you can adapt it precisely to your requirements. However in order to
quickly try out the Corfu completion package, it should be sufficient to
global-corfu-mode. You can experiment with manual completion for
example in an Elisp buffer or in an Eshell or Shell buffer. For auto completion,
corfu-auto=t before turning on
Here is an example configuration:
(use-package corfu ;; Optional customizations ;; :custom ;; (corfu-cycle t) ;; Enable cycling for `corfu-next/previous' ;; (corfu-auto t) ;; Enable auto completion ;; (corfu-separator ?\s) ;; Orderless field separator ;; (corfu-quit-at-boundary nil) ;; Never quit at completion boundary ;; (corfu-quit-no-match nil) ;; Never quit, even if there is no match ;; (corfu-preview-current nil) ;; Disable current candidate preview ;; (corfu-preselect-first nil) ;; Disable candidate preselection ;; (corfu-on-exact-match nil) ;; Configure handling of exact matches ;; (corfu-echo-documentation nil) ;; Disable documentation in the echo area ;; (corfu-scroll-margin 5) ;; Use scroll margin ;; Enable Corfu only for certain modes. ;; :hook ((prog-mode . corfu-mode) ;; (shell-mode . corfu-mode) ;; (eshell-mode . corfu-mode)) ;; Recommended: Enable Corfu globally. ;; This is recommended since Dabbrev can be used globally (M-/). ;; See also `corfu-excluded-modes'. :init (global-corfu-mode)) ;; A few more useful configurations... (use-package emacs :init ;; TAB cycle if there are only few candidates (setq completion-cycle-threshold 3) ;; Emacs 28: Hide commands in M-x which do not apply to the current mode. ;; Corfu commands are hidden, since they are not supposed to be used via M-x. ;; (setq read-extended-command-predicate ;; #'command-completion-default-include-p) ;; Enable indentation+completion using the TAB key. ;; `completion-at-point' is often bound to M-TAB. (setq tab-always-indent 'complete))
Dabbrev completion is based on
completion-in-region and can be used with Corfu.
You may want to swap the
dabbrev-completion with the
dabbrev-expand key for
easier access, if you prefer completion. Also take a look at the
completion at point function provided by my Cape package.
;; Use Dabbrev with Corfu! (use-package dabbrev ;; Swap M-/ and C-M-/ :bind (("M-/" . dabbrev-completion) ("C-M-/" . dabbrev-expand)) ;; Other useful Dabbrev configurations. :custom (dabbrev-ignored-buffer-regexps '("\\.\\(?:pdf\\|jpe?g\\|png\\)\\'")))
If you start to configure the package more deeply, I recommend to give the Orderless completion style a try for filtering. Orderless completion is different from the familiar prefix TAB completion. Corfu can be used with the default completion styles. The use of Orderless is not a necessity.
;; Optionally use the `orderless' completion style. (use-package orderless :init ;; Configure a custom style dispatcher (see the Consult wiki) ;; (setq orderless-style-dispatchers '(+orderless-dispatch) ;; orderless-component-separator #'orderless-escapable-split-on-space) (setq completion-styles '(orderless basic) completion-category-defaults nil completion-category-overrides '((file (styles . (partial-completion))))))
basic completion style is specified as fallback in addition to
order to ensure that completion commands which rely on dynamic completion
+orderless-dispatch in the Consult wiki for an advanced Orderless
style dispatcher. Additionally enable
partial-completion for file path
partial-completion is important for file wildcard support. Multiple
files can be opened at once with
find-file if you enter a wildcard. You may also
initials completion style a try.
See also the Corfu Wiki and the Cape manual for additional Capf configuration tips. The Lsp-mode configuration is documented in the wiki. For more general documentation read the chapter about completion in the Emacs manual. If you want to create your own Capfs, you can find documentation about completion in the Elisp manual.
Auto completion is disabled by default, but can be enabled by setting
corfu-auto=t. Furthermore you may want to configure Corfu to quit completion
eagerly, such that the completion popup stays out of your way when it appeared
;; Enable auto completion and configure quitting (setq corfu-auto t corfu-quit-no-match 'separator) ;; or t
I recommend to experiment a bit with the various settings and key bindings to find a configuration which works for you. There is no one size fits all solution. Some people like auto completion, some like manual completion, some want to cycle with TAB and some with the arrow keys.
In case you like aggressive auto completion settings, where the completion popup
appears immediately, I recommend to use a cheap completion style like
which performs prefix filtering. In this case Corfu completion should still be
very fast in buffers with efficient completion backends. You can try the
following settings in an Elisp buffer or the Emacs scratch buffer.
;; Aggressive completion, cheap prefix filtering. (setq-local corfu-auto t corfu-auto-delay 0 corfu-auto-prefix 0 completion-styles '(basic))
If you want to combine fast prefix filtering and Orderless filtering you can
still do that by defining a custom Orderless completion style via
orderless-define-completion-style. We use a custom style dispatcher, which
enables prefix filtering for input shorter than 4 characters. Note that such a
setup is quite advanced. Please refer to the Orderless documentation and source
code for further details.
(defun orderless-fast-dispatch (word index total) (and (= index 0) (= total 1) (length< word 4) `(orderless-regexp . ,(concat "^" (regexp-quote word))))) (orderless-define-completion-style orderless-fast (orderless-style-dispatchers '(orderless-fast-dispatch)) (orderless-matching-styles '(orderless-literal orderless-regexp))) (setq-local corfu-auto t corfu-auto-delay 0 corfu-auto-prefix 0 completion-styles '(orderless-fast))
Corfu can be used for completion in the minibuffer, since it relies on child
frames to display the candidates. By default,
global-corfu-mode does not
corfu-mode in the minibuffer, to avoid interference with specialised
minibuffer completion UIs like Vertico or Mct. However you may still want to
enable Corfu completion for commands like
shell-command), which read from the minibuffer. Activate
corfu-mode only if
completion-at-point is bound in the minibuffer-local keymap to achieve this
(defun corfu-enable-in-minibuffer () "Enable Corfu in the minibuffer if `completion-at-point' is bound." (when (where-is-internal #'completion-at-point (list (current-local-map))) ;; (setq-local corfu-auto nil) Enable/disable auto completion (corfu-mode 1))) (add-hook 'minibuffer-setup-hook #'corfu-enable-in-minibuffer)
You can also enable Corfu more generally for every minibuffer, as long as no other completion UI is active. If you use Mct or Vertico as your main minibuffer completion UI, the following snippet should yield the desired result.
(defun corfu-enable-always-in-minibuffer () "Enable Corfu in the minibuffer if Vertico/Mct are not active." (unless (or (bound-and-true-p mct--active) (bound-and-true-p vertico--input)) ;; (setq-local corfu-auto nil) Enable/disable auto completion (corfu-mode 1))) (add-hook 'minibuffer-setup-hook #'corfu-enable-always-in-minibuffer 1)
When completing in the Eshell I recommend conservative local settings without auto completion, such that the completion behavior is similar to widely used shells like Bash, Zsh or Fish.
(add-hook 'eshell-mode-hook (lambda () (setq-local corfu-auto nil) (corfu-mode)))
RET while the Corfu popup is visible, the
will be invoked. This command does inserts the currently selected candidate, but
it does not send the prompt input to Eshell or the comint process. Therefore you
often have to press
RET twice which feels like an unnecessary double
confirmation. Fortunately it is easy to improve this! In my configuration I
define the advice
corfu-send-shell which sends the candidate after insertion.
(defun corfu-send-shell (&rest _) "Send completion candidate when inside comint/eshell." (cond ((and (derived-mode-p 'eshell-mode) (fboundp 'eshell-send-input)) (eshell-send-input)) ((and (derived-mode-p 'comint-mode) (fboundp 'comint-send-input)) (comint-send-input)))) (advice-add #'corfu-insert :after #'corfu-send-shell)
Shell completion uses the flexible
Pcomplete mechanism internally, which allows
you to program the completions per shell command. If you want to know more, look
into this blog post, which shows how to configure Pcomplete for git commands. I
recommend the pcmpl-args package which extends Pcomplete with completion support
and helpful annotation support for more commands. Similar to the Fish shell,
pcmpl-args uses man page parsing and –help output parsing to dynamically
generate completions. This package brings Eshell completion to another level!
Unfortunately Pcomplete has a few technical issues, which we can work around with the Cape library (Completion at point extensions). Cape provides wrappers, which sanitize the Pcomplete function. Ideally the bugs in Pcomplete should be fixed upstream. For now these two advices are strongly recommended to achieve a sane Eshell experience.
;; Silence the pcomplete capf, no errors or messages! (advice-add 'pcomplete-completions-at-point :around #'cape-wrap-silent) ;; Ensure that pcomplete does not write to the buffer ;; and behaves as a pure `completion-at-point-function'. (advice-add 'pcomplete-completions-at-point :around #'cape-wrap-purify)
Orderless is an advanced completion style that supports multi-component search filters separated by a configurable character (space, by default). Normally, entering characters like space which lie outside the completion region boundaries (words, typically) causes Corfu to quit. This behavior is helpful with auto-completion, which may pop-up when not desired, e.g. on entering a new variable name. Just keep typing and Corfu will get out of the way.
But orderless search terms can contain arbitrary characters; they are also
interpreted as regular expressions. To use orderless, set
space, by default) to the primary character of your orderless component
Then, when a new orderless component is desired, use
corfu-insert-separator) to enter the first component separator in the input,
and arbitrary orderless search terms and new separators can be entered
To treat the entire input as Orderless input, you can set the customization
corfu-quit-at-boundary=t. This disables the predicate which checks if the
current completion boundary has been left. In contrast, if you always want to
quit at the boundary, simply set
corfu-quit-at-boundary=nil. By default
corfu-quit-at-boundary is set to
separator which quits at completion boundaries
as long as no separator has been inserted with
Finally, there exists the user option
corfu-quit-no-match which is set to
separator by default. With this setting Corfu stays alive as soon as you start
advanced filtering with a
corfu-separator even if there are no matches, for
example due to a typo. As long as no separator character has been inserted with
corfu-insert-separator, Corfu will still quit if there are no matches. This
ensures that the Corfu popup goes away quickly if completion is not possible.
In the following we show two configurations, one which works best with auto
completion and one which may work better with manual completion if you prefer to
SPC to separate the Orderless components.
;; Auto completion example (use-package corfu :custom (corfu-auto t) ;; Enable auto completion ;; (corfu-separator ?_) ;; Set to orderless separator, if not using space :bind ;; Another key binding can be used, such as S-SPC. ;; (:map corfu-map ("M-SPC" . corfu-insert-separator)) :init (global-corfu-mode)) ;; Manual completion example (use-package corfu :custom ;; (corfu-separator ?_) ;; Set to orderless separator, if not using space :bind ;; Configure SPC for separator insertion (:map corfu-map ("SPC" . corfu-insert-separator)) :init (global-corfu-mode))
You may be interested in configuring Corfu in TAB-and-Go style. Pressing TAB
moves to the next candidate and further input will then commit the selection.
Note that further input will not expand snippets or templates, which may not be
desired but which leads overall to a more predictable behavior. In order to
force snippet expansion, confirm a candidate explicitly with
(use-package corfu ;; TAB-and-Go customizations :custom (corfu-cycle t) ;; Enable cycling for `corfu-next/previous' (corfu-preselect-first nil) ;; Disable candidate preselection ;; Use TAB for cycling, default is `corfu-complete'. :bind (:map corfu-map ("TAB" . corfu-next) ([tab] . corfu-next) ("S-TAB" . corfu-previous) ([backtab] . corfu-previous)) :init (global-corfu-mode))
Sometimes it is useful to transfer the Corfu completion session to the minibuffer, since the minibuffer offers richer interaction features. In particular, Embark is available in the minibuffer, such that you can act on the candidates or export/collect the candidates to a separate buffer. Hopefully we can also add Corfu-support to Embark in the future, such that at least export/collect is possible directly from Corfu. But in my opinion having the ability to transfer the Corfu completion to the minibuffer is an even better feature, since further completion can be performed there.
corfu-move-to-minibuffer is defined here in terms of
consult-completion-in-region, which uses the minibuffer completion UI via
(defun corfu-move-to-minibuffer () (interactive) (let ((completion-extra-properties corfu--extra) completion-cycle-threshold completion-cycling) (apply #'consult-completion-in-region completion-in-region--data))) (define-key corfu-map "\M-m" #'corfu-move-to-minibuffer)
Corfu uses a transient keymap
corfu-map which is active while the popup is
shown. The keymap defines the following remappings and bindings:
We maintain small extension packages to Corfu in this repository in the
subdirectory extensions/. The extensions are installed together with Corfu if
you pull the package from ELPA. The extensions are inactive by default and can
be enabled manually if desired. Furthermore it is possible to install all of the
files separately, both
corfu.el and the
corfu-*.el extensions. Currently the
following extensions come with the Corfu ELPA package:
corfu-history-modeto remember selected candidates and to improve sorting.
corfu-indexed-modeto select indexed candidates with prefix arguments.
See the Commentary of those files for configuration details.
Corfu works well together with all packages providing code completion via the
completion-at-point-functions. Many modes and packages already provide a Capf
out of the box. Nevertheless you may want to look into complementary packages to
enhance your setup.
completion-in-regioncommands are provided by the Cape package. Among others, the package supplies a file path and a Dabbrev completion backend. Cape provides the
cape-company-to-capfadapter to reuse Company backends in Corfu. Furthermore the function
cape-super-capfcan merge multiple Capfs, such that the candidates of multiple Capfs are displayed together at the same time.
completion-stylessupport is more limited and the
completion-at-pointcommand and the
completion-in-regionfunction do not invoke Company.
consult-completion-in-regionwhich can be set as
completion-in-region-functionsuch that it handles
completion-at-point. The function works by transferring the in-buffer completion to the minibuffer. In the minibuffer, the minibuffer completion UI, for example Vertico takes over. If you prefer to perform all your completions in the minibuffer
consult-completion-in-regionis your best option.
Since this package is part of GNU ELPA contributions require a copyright assignment to the FSF.