Corfu enhances in-buffer completion with a small completion popup. The current candidates are shown in a popup below or above the point. The candidates can be selected by moving up and down. Corfu is the minimalistic in-buffer completion 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. In-buffer completion UIs in
Emacs can hook into completion-in-region
, which implements the interaction with
the user. Completions at point are either provided by commands like
dabbrev-completion
or by pluggable backends (completion-at-point-functions
,
Capfs) and are then passed to completion-in-region
. Many programming, text and
shell major modes implement a Capf. Corfu does not include its own completion
backends. The Emacs built-in Capfs and the Capfs provided by third-party
programming language packages are often sufficient. 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.
- Timer-based auto-completions (off by default, set
corfu-auto
). - Popup display with scrollbar indicator and arrow key navigation.
- The popup can be summoned explicitly by pressing
TAB
at any time. - The current candidate is inserted with
TAB
and selected withRET
. - Candidate sorting by prefix, string length and alphabetically.
- The selected candidate is previewed (configurable via
corfu-preview-current
). - The selected candidate is automatically committed on further input by default.
(configurable via
corfu-preview-current
). - Supports the Orderless completion style. The filter string can contain
arbitrary characters, after inserting a space via
M-SPC
(configurable viacorfu-quit-at-boundary
andcorfu-separator
). - Lazy completion candidate highlighting for performance.
- Support for candidate annotations (
annotation-function
,affixation-function
). - Deprecated candidates are displayed as crossed out.
- Icons can be provided by an external package via margin formatter functions.
- Rich set of extensions: Quick keys, Index keys, Sorting by history, Candidate documentation in echo area, popup or separate buffer.
Corfu is available from GNU ELPA. You can install it directly via M-x package-install RET corfu RET
.
After installation, activate the global minor mode with M-x global-corfu-mode RET
.
Set the variable corfu-auto
to t in order to enable auto completion. For manual
completion press M-TAB
(or TAB
) within a buffer.
Corfu uses a transient keymap corfu-map
which is active while the popup is
shown. The keymap defines the following remappings of fundamental commands and
bindings:
Binding/Remapping | Corfu command |
---|---|
move-beginning-of-line | corfu-prompt-beginning |
move-end-of-line | corfu-prompt-end |
beginning-of-buffer | corfu-first |
end-of-buffer | corfu-last |
scroll-down-command | corfu-scroll-down |
scroll-up-command | corfu-scroll-up |
next-line , down , M-n | corfu-next |
previous-line , up , M-p | corfu-previous |
completion-at-point , TAB | corfu-complete |
M-TAB | corfu-expand |
RET | corfu-insert |
M-g | corfu-info-location |
M-h | corfu-info-documentation |
M-SPC | corfu-insert-separator |
C-g | corfu-quit |
keyboard-escape-quit | corfu-reset |
In order to configure Corfu and other packages in your init.el, you may want to
use use-package
. Corfu is flexibly 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 activate 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,
set corfu-auto
to t before turning on global-corfu-mode
.
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 'prompt) ;; Preselect the prompt
;; (corfu-on-exact-match nil) ;; Configure handling of exact matches
;; (corfu-scroll-margin 5) ;; Use scroll margin
;; Enable Corfu only for certain modes. See also `global-corfu-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 the customization variable
;; `global-corfu-modes' to exclude certain modes.
:init
(global-corfu-mode))
;; A few more useful configurations...
(use-package emacs
:custom
;; TAB cycle if there are only few candidates
;; (completion-cycle-threshold 3)
;; Enable indentation+completion using the TAB key.
;; `completion-at-point' is often bound to M-TAB.
(tab-always-indent 'complete)
;; Emacs 30 and newer: Disable Ispell completion function. As an alternative,
;; try `cape-dict'.
(text-mode-ispell-word-completion nil)
;; Emacs 28 and newer: Hide commands in M-x which do not apply to the current
;; mode. Corfu commands are hidden, since they are not used via M-x. This
;; setting is useful beyond Corfu.
(read-extended-command-predicate #'command-completion-default-include-p))
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 cape-dabbrev
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))
:config
(add-to-list 'dabbrev-ignored-buffer-regexps "\\` ")
;; Since 29.1, use `dabbrev-ignored-buffer-regexps' on older.
(add-to-list 'dabbrev-ignored-buffer-modes 'doc-view-mode)
(add-to-list 'dabbrev-ignored-buffer-modes 'pdf-view-mode)
(add-to-list 'dabbrev-ignored-buffer-modes 'tags-table-mode))
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
:custom
;; Configure a custom style dispatcher (see the Consult wiki)
;; (orderless-style-dispatchers '(+orderless-dispatch))
;; (orderless-component-separator #'orderless-escapable-split-on-space)
(completion-styles '(orderless basic))
(completion-category-defaults nil)
(completion-category-overrides '((file (styles partial-completion)))))
The basic
completion style is specified as fallback in addition to orderless
in
order to ensure that completion commands which rely on dynamic completion
tables, e.g., completion-table-dynamic
or completion-table-in-turn
, work
correctly. See +orderless-dispatch
in the Consult wiki for an advanced Orderless
style dispatcher. Additionally enable partial-completion
for file path
expansion. 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
give the initials
completion style a try.
See also the Corfu Wiki and the Cape manual for additional Capf configuration tips. 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
to 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
unexpectedly.
;; Enable auto completion and configure quitting
(setq corfu-auto t
corfu-quit-no-match 'separator) ;; or t
I suggest to experiment with the various settings and key bindings to find a configuration which works for you. There is no one perfect configuration which fits all. 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 auto completion settings, where the completion popup appears
immediately, better use a cheap completion style like basic
, which performs
prefix filtering. In this case Corfu completion should still be fast in buffers
with efficient completion backends. You can try the following settings in an
Elisp buffer or the Emacs scratch buffer. Note that such settings can slow down
Emacs due to the high load on the Lisp runtime and garbage collector.
(setq-local corfu-auto t
corfu-auto-delay 0 ;; TOO SMALL - NOT RECOMMENDED
corfu-auto-prefix 1 ;; TOO SMALL - NOT RECOMMENDED
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 efficient prefix filtering for input shorter than 4 characters. Note
that such a setup is 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)
(cons 'orderless-literal-prefix 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 ;; TOO SMALL - NOT RECOMMENDED
corfu-auto-prefix 1 ;; TOO SMALL - NOT RECOMMENDED
completion-styles '(orderless-fast basic))
Corfu can be used for completion in the minibuffer, since it relies on child frames to display the candidates. The Corfu popup can be shown even if it doesn’t fully fit inside the minibuffer.
global-corfu-mode
activates corfu-mode
in the minibuffer if the variable
global-corfu-minibuffer
is non-nil. In order to avoid interference with
specialised minibuffer completion UIs like Vertico or Mct, Corfu is only enabled
if the minibuffer sets the variable completion-at-point-functions
locally. This
way minibuffers with completion can be detected, such that minibuffer commands
like M-:
(eval-expression
) or M-!
(shell-command
) are enhanced with Corfu
completion.
If needed, one can also enable Corfu more generally in all minibuffers, as long
as no completion UI is active. In the following example we set
global-corfu-minibuffer
to a predicate function, which checks for Mct and
Vertico. Furthermore we ensure that Corfu is not enabled if a password is read
from the minibuffer.
(setq global-corfu-minibuffer
(lambda ()
(not (or (bound-and-true-p mct--active)
(bound-and-true-p vertico--input)
(eq (current-local-map) read-passwd-map)))))
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)))
When pressing RET
while the Corfu popup is visible, the corfu-insert
command
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 by using the command
corfu-send
instead.
(keymap-set corfu-map "RET" #'corfu-send)
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.
Since Emacs 29, Pcomplete offers the pcomplete-from-help
function which parses
the --help
output of a command and produces completions for command line
options.
Pcomplete has a few bugs on Emacs 28 and older. We can work around the issues with the Cape library (Completion at point extensions). Cape provides wrappers which sanitize the Pcomplete function. On Emacs 29 the advices should not be necessary anymore, since most relevant bugs have been fixed. In case you discover any remaining Pcomplete issues, please report them upstream.
;; Sanitize the `pcomplete-completions-at-point' Capf. The Capf has undesired
;; side effects on Emacs 28 and earlier. These advices are not needed on Emacs
;; 29 and newer.
(when (< emacs-major-version 29)
(advice-add 'pcomplete-completions-at-point :around #'cape-wrap-silent)
(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 corfu-separator
(a
space, by default) to the primary character of your orderless component
separator.
Then, when a new orderless component is desired, use M-SPC
(corfu-insert-separator
) to enter the first component separator in the input,
and arbitrary orderless search terms and new separators can be entered
thereafter.
To treat the entire input as Orderless input, you can set the customization
option corfu-quit-at-boundary
to nil. 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, set corfu-quit-at-boundary
to t. By default
corfu-quit-at-boundary
is set to separator
which quits at completion boundaries
as long as no separator has been inserted with corfu-insert-separator
.
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
always use 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))
By default, Corfu steals both the RET
and TAB
keys, when the Corfu popup is
open. This can feel intrusive, in particular in combination with auto
completion. RET
may accidentally commit an automatically selected candidate,
while you actually wanted to start a new line. As an alternative we can unbind
the RET
key completely from corfu-map
or reserve the RET
key only in shell
modes using a menu-item filter.
;; TAB-only configuration
(use-package corfu
:custom
(corfu-auto t) ;; Enable auto completion
(corfu-preselect 'directory) ;; Select the first candidate, except for directories
:init
(global-corfu-mode)
:config
;; Free the RET key for less intrusive behavior.
;; Option 1: Unbind RET completely
;; (keymap-unset corfu-map "RET")
;; Option 2: Use RET only in shell modes
(keymap-set corfu-map "RET" `( menu-item "" nil :filter
,(lambda (&optional _)
(and (derived-mode-p 'eshell-mode 'comint-mode)
#'corfu-send)))))
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 RET
.
(use-package corfu
;; TAB-and-Go customizations
:custom
(corfu-cycle t) ;; Enable cycling for `corfu-next/previous'
(corfu-preselect 'prompt) ;; Always preselect the prompt
;; 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))
If you leave the default configuration of the completion styles, such that the
basic
completion style is still present, then pressing M-TAB
(corfu-expand
) will
expand the current input to the common prefix of all completion candidates. In
contrast, TAB
(corfu-complete
) behaves differently and expands input to the
currently selected candidate.
If you use the orderless
completion style, then expansion works differently by
default. Orderless only expands to single matching candidates, since due to its
multi-component input, there does not necessarily exist an expansion to a common
candidate prefix. However it is possible to define a separate tab
completion
style. The tab
completion style will only take over TAB
completion (if prefix
expansion is possible), but besides that won’t affect Orderless candidate
filtering.
(add-to-list 'completion-styles-alist
'(tab completion-basic-try-completion ignore
"Completion style which provides TAB completion only."))
(setq completion-styles '(tab orderless basic)))
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. We could add Corfu support to Embark in the future, such that export or collect is possible directly from Corfu. Nevertheless, the ability to transfer the Corfu completion to the minibuffer is even more powerful, since further completion is possible.
The command corfu-move-to-minibuffer
is defined here in terms of
consult-completion-in-region
, which uses the minibuffer completion UI via
completing-read
.
(defun corfu-move-to-minibuffer ()
(interactive)
(pcase completion-in-region--data
(`(,beg ,end ,table ,pred ,extras)
(let ((completion-extra-properties extras)
completion-cycle-threshold completion-cycling)
(consult-completion-in-region beg end table pred)))))
(keymap-set corfu-map "M-m" #'corfu-move-to-minibuffer)
(add-to-list 'corfu-continue-commands #'corfu-move-to-minibuffer)
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-echo:
corfu-echo-mode
displays a brief candidate documentation in the echo area. - corfu-history:
corfu-history-mode
remembers selected candidates and sorts the candidates by their history position. - corfu-indexed:
corfu-indexed-mode
allows you to select indexed candidates with prefix arguments. - corfu-info: Actions to access the candidate location and documentation.
- corfu-popupinfo: Display candidate documentation or source in a popup next to the candidate menu.
- corfu-quick: Commands to select using Avy-style quick keys.
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.
- corfu-terminal: The corfu-terminal package provides an overlay-based display for Corfu, such that you can use Corfu in terminal Emacs.
- corfu-candidate-overlay: Shows as-you-type auto-suggestion candidate overlay
with a visual indication of whether there are many or exactly one candidate
available (works only with
corfu-auto
disabled). - Orderless: Corfu supports completion styles, including the advanced
orderless
completion style, where the filter expressions are separated by spaces or another character (seecorfu-separator
). - Cape: Provides additional Capf backends and
completion-in-region
commands. Among others, the package supplies the file completion backendcape-file
and the Dabbrev backendcape-dabbrev
. Cape provides thecape-company-to-capf
adapter to reuse Company backends in Corfu. - nerd-icons-corfu, kind-icon: Icons are supported by Corfu via external packages. The nerd-icons-corfu package relies on the Nerd icon font, which is even supported on terminal, while kind-icon uses SVGs from monochromatic icon sets.
- Tempel: Tiny template/snippet package with templates in Lisp syntax, which can be used in conjunction with Corfu.
- Vertico: You may also want to look into my Vertico package. Vertico is the minibuffer completion counterpart of Corfu.
- Company: Company is a widely used and mature completion package, which
implements a similar UI as Corfu. While Corfu relies exclusively on the
standard Emacs completion API (Capfs), Company defines its own API for the
backends. Company includes its own completion backends, following its own API,
which are incompatible with the Emacs completion infrastructure. Company
provides an adapter
company-capf
to handle Capfs as a Company backend. As a result of this design, Company is a more complex package than Corfu. Company by default uses overlays for the popup in contrast to the child frames used by Corfu. Overall both packages work well, but Company integrates less tightly with Emacs. Thecompletion-styles
support is more limited and thecompletion-at-point
command and thecompletion-in-region
function do not invoke Company. - consult-completion-in-region: The Consult package provides the function
consult-completion-in-region
which can be set ascompletion-in-region-function
such that it handlescompletion-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 minibufferconsult-completion-in-region
is your best option.
When you observe an error in the corfu--post-command
post command hook, you
should install an advice to enforce debugging. This allows you to obtain a stack
trace in order to narrow down the location of the error. The reason is that post
command hooks are automatically disabled (and not debugged) by Emacs. Otherwise
Emacs would become unusable, given that the hooks are executed after every
command.
(setq debug-on-error t)
(defun force-debug (func &rest args)
(condition-case e
(apply func args)
((debug error) (signal (car e) (cdr e)))))
(advice-add #'corfu--post-command :around #'force-debug)
When Capfs do not yield the expected result you can use cape-capf-debug
to add
debug messages to a Capf. The Capf will then produce a completion log in the
messages buffer.
(setq completion-at-point-functions (list (cape-capf-debug #'cape-dict)))
Since this package is part of GNU ELPA contributions require a copyright assignment to the FSF.