#+TEXINFO_DIR_DESC: Using Ivy for completion.
#+SETUPFILE: ~/git/org-html-themes/setup/theme-readtheorg.setup
#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="kbd-style.css"/>
-#+EXPORT_FILE_NAME: index.html
-
#+OPTIONS: H:6 num:6 toc:4
#+STARTUP: indent
* Setup :noexport:
(require 'ivy-ox)
#+END_SRC
* Writing this manual :noexport:
-For highlighting a section without introducing a new subheading use
-definition lists. The definition list "owns" the following text if the
-text is indented by 5 spaces. Use ~C-q~ to indent these
-paragraphs. New paragraphs can also be started, as long as they have
-the 5 spaces indent.
+To highlight a section without introducing a new subheading use
+definition lists. The definition list "owns" the subsequent text if
+the text is indented by 5 spaces. Use ~C-q~ to indent the
+paragraphs. Start new paragraphs with 5 spaces indented. To separate
+definition lists from regular lists, use two newlines.
+
+A typical definition list:
+#+BEGIN_EXAMPLE
+- ~C-M-j~ (=ivy-immediate-done=) ::
+#+END_EXAMPLE
+The code and kbd part is recognized and added as =@vindex= and
+=@kindex= respectively.
-For declaring a =@defopt= section for =defcustom= or =defvar=, also
-use definition lists. They need to have the following form in order to
-be recognized in the texinfo export:
+Use definition lists to declare a =@defopt= section for =defcustom=
+or =defvar=. For proper Texinfo export, use this form:
#+BEGIN_EXAMPLE
User Option =ivy-wrap= ::
#+END_EXAMPLE
-To name each heading, set its =CUSTOM_ID= property. This can be done
-easily with =worf='s ~C-u L~.
+Set =CUSTOM_ID= property to name each heading. For example, =worf='s
+~C-u L~. This will result in consistent HTML node names.
+Keep one empty line before each source block for proper Texinfo
+exports.
* Copying
:PROPERTIES:
:COPYING: t
- Minimalism ::
Uncluttered minibuffer is minimalism. Ivy shows the completion
defaults, the number of matches, and 10 candidate matches below
- the input line. Customize =ivy-length= to adjust the number of
+ the input line. Customize =ivy-height= to adjust the number of
candidate matches displayed in the minibuffer.
- Simplicity ::
Install Ivy automatically through Emacs's package manager, or manually
from Ivy's development repository.
+Emacs 24.3.1 is the oldest version to run Ivy. Emacs 24.5.1 is the
+oldest version that runs Ivy with fancy faces display.
+
** Installing from Emacs Package Manager
:PROPERTIES:
:CUSTOM_ID: installing-from-emacs-package-manager
:CUSTOM_ID: installing-from-the-git-repository
:END:
-Why install from Git?
+- Why install from Git? ::
-- No need to wait for MELPA's hourly builds
-- Easy to revert to previous versions
-- Contribute to Ivy's development; send patches; pull requests
+ - No need to wait for MELPA's hourly builds
+ - Easy to revert to previous versions
+ - Contribute to Ivy's development; send patches; pull requests
-*Configuration steps*
-First clone the Swiper repository:
-#+begin_src sh
-cd ~/git && git clone https://github.com/abo-abo/swiper
-cd swiper && make compile
-#+end_src
+- Configuration steps ::
+ First clone the Swiper repository with:
-Then add this to Emacs init:
-#+begin_src elisp
-(add-to-list 'load-path "~/git/swiper/")
-(require 'ivy)
-#+end_src
+ #+begin_src sh
+ cd ~/git && git clone https://github.com/abo-abo/swiper
+ cd swiper && make compile
+ #+end_src
-To update the code:
-#+begin_src sh
-git pull
-make
-#+end_src
+ Second, add these lines to the Emacs init file:
+
+ #+begin_src elisp
+ (add-to-list 'load-path "~/git/swiper/")
+ (require 'ivy)
+ #+end_src
+
+ Then, update the code with:
+
+ #+begin_src sh
+ git pull
+ make
+ #+end_src
* Getting started
:PROPERTIES:
:CUSTOM_ID: getting-started
:END:
-First, enable Ivy completion everywhere:
+First enable Ivy completion everywhere:
#+begin_src elisp
(ivy-mode 1)
:PROPERTIES:
:CUSTOM_ID: basic-customization
:END:
-Here are some basic settings particularly useful for new Ivy
-users:
+Here are some basic settings particularly useful for new Ivy users:
+
#+begin_src elisp
(setq ivy-use-virtual-buffers t)
(setq ivy-height 10)
-(setq ivy-display-style 'fancy)
(setq ivy-count-format "(%d/%d) ")
#+end_src
-For additional customizations, refer to =M-x describe-variable=
+If you want, you can go without any customizations at all. The above
+settings are the most bang for the buck in terms of customization. So
+users that typically don't like customize a lot are advised to look at
+these settings first.
+
+For more advanced customizations, refer to =M-x describe-variable=
documentation.
* Key bindings
The recommended key bindings are:
- Ivy-based interface to standard commands ::
-#+begin_src elisp
-(global-set-key (kbd "C-s") 'swiper)
-(global-set-key (kbd "M-x") 'counsel-M-x)
-(global-set-key (kbd "C-x C-f") 'counsel-find-file)
-(global-set-key (kbd "<f1> f") 'counsel-describe-function)
-(global-set-key (kbd "<f1> v") 'counsel-describe-variable)
-(global-set-key (kbd "<f1> l") 'counsel-load-library)
-(global-set-key (kbd "<f2> i") 'counsel-info-lookup-symbol)
-(global-set-key (kbd "<f2> u") 'counsel-unicode-char)
-#+end_src
+
+ #+begin_src elisp
+ (global-set-key (kbd "C-s") 'swiper)
+ (global-set-key (kbd "M-x") 'counsel-M-x)
+ (global-set-key (kbd "C-x C-f") 'counsel-find-file)
+ (global-set-key (kbd "<f1> f") 'counsel-describe-function)
+ (global-set-key (kbd "<f1> v") 'counsel-describe-variable)
+ (global-set-key (kbd "<f1> l") 'counsel-load-library)
+ (global-set-key (kbd "<f2> i") 'counsel-info-lookup-symbol)
+ (global-set-key (kbd "<f2> u") 'counsel-unicode-char)
+ #+end_src
- Ivy-based interface to shell and system tools ::
-#+begin_src elisp
-(global-set-key (kbd "C-c g") 'counsel-git)
-(global-set-key (kbd "C-c j") 'counsel-git-grep)
-(global-set-key (kbd "C-c k") 'counsel-ag)
-(global-set-key (kbd "C-x l") 'counsel-locate)
-(global-set-key (kbd "C-S-o") 'counsel-rhythmbox)
-#+end_src
+
+ #+begin_src elisp
+ (global-set-key (kbd "C-c g") 'counsel-git)
+ (global-set-key (kbd "C-c j") 'counsel-git-grep)
+ (global-set-key (kbd "C-c k") 'counsel-ag)
+ (global-set-key (kbd "C-x l") 'counsel-locate)
+ (global-set-key (kbd "C-S-o") 'counsel-rhythmbox)
+ #+end_src
- Ivy-resume and other commands ::
-=ivy-resume= resumes the last Ivy-based completion.
-#+begin_src elisp
-(global-set-key (kbd "C-c C-r") 'ivy-resume)
-#+end_src
+
+ =ivy-resume= resumes the last Ivy-based completion.
+
+ #+begin_src elisp
+ (global-set-key (kbd "C-c C-r") 'ivy-resume)
+ #+end_src
** Minibuffer key bindings
:PROPERTIES:
:CUSTOM_ID: minibuffer-key-bindings
:END:
+#+VINDEX: ivy-minibuffer-map
Ivy includes several minibuffer bindings, which are defined in the
=ivy-minibuffer-map= keymap variable. The most frequently used ones
are described here.
-=swiper= or =counsel-M-x= add more through the =keymap= argument to
-=ivy-read=. These keys, also active in the minibuffer, are described
-under their respective commands.
+=swiper= or =counsel-M-x= add more key bindings through the =keymap=
+argument to =ivy-read=. These keys, also active in the minibuffer, are
+described under their respective commands.
+
+A key feature of =ivy-minibuffer-map= is its full editing capability
+where the familiar ~C-a~, ~C-f~, ~M-d~, ~M-DEL~, ~M-b~, ~M-w~, ~C-k~,
+~C-y~ key bindings work the same as in =fundamental-mode=.
*** Key bindings for navigation
:PROPERTIES:
- User Option =ivy-wrap= ::
- This user option allows to get the wrap-around behavior for ~C-n~
- and ~C-p~. When set to =t=, =ivy-next-line= and
- =ivy-previous-line= will cycle past the last and the first
- candidates respectively.
+ Specifies the wrap-around behavior for ~C-n~ and ~C-p~. When
+ =ivy-wrap= is set to =t=, =ivy-next-line= and =ivy-previous-line=
+ will cycle past the last and the first candidates respectively.
- This behavior is off by default.
+ Warp-around behavior is off by default.
- User Option =ivy-height= ::
- Use this variable to adjust the minibuffer height, and therefore
- the scroll size for ~C-v~ and ~M-v~.
+ Use this option to adjust the minibuffer height, which also
+ affects scroll size when using ~C-v~ and ~M-v~ key bindings.
+ =ivy-height= is 10 lines by default.
*** Key bindings for single selection, action, then exit minibuffer
:PROPERTIES:
extends usability of lists in Emacs.
- ~C-m~ or ~RET~ (=ivy-done=) ::
- Calls the default action and exits the minibuffer.
+ Calls the default action and then exits the minibuffer.
- ~M-o~ (=ivy-dispatching-done=) ::
- Presents all available valid actions from which to choose. When
- there is only one action available, there is no difference
- between ~M-o~ and ~C-m~.
+ Presents valid actions from which to choose. When only one action
+ is available, there is no difference between ~M-o~ and ~C-m~.
- ~C-j~ (=ivy-alt-done=) ::
When completing file names, selects the current directory
candidate and starts a new completion session there. Otherwise,
- it's the same as =ivy-done=.
+ it is the same as =ivy-done=.
- ~TAB~ (=ivy-partial-or-done=) ::
Attempts partial completion, extending current input as much as
- possible. ~TAB TAB~ is the same as ~C-j~.
+ possible. ~TAB TAB~ is the same as ~C-j~ (=ivy-alt-done=).
+
+ Example ERT test:
+
+ #+begin_src elisp
+ (should
+ (equal (ivy-with
+ '(progn
+ (ivy-read "Test: " '("can do" "can't, sorry" "other"))
+ ivy-text)
+ "c <tab>")
+ "can"))
+ #+end_src
- ~C-M-j~ (=ivy-immediate-done=) ::
Exits with /the current input/ instead of /the current candidate/
other direction.
- =ivy-resume= ::
- Recalls the state of the completion session just before its last exit.
+ Recalls the state of the completion session just before its last
+ exit.
Useful after an accidental ~C-m~ (=ivy-done=).
- ~M-w~ (=ivy-kill-ring-save=) ::
Copies selected candidates to the kill ring.
- When the region is active, copies active region instead.
+ Copies the region if the region is active.
*** Hydra in the minibuffer
:PROPERTIES:
- ~C-o~ (=hydra-ivy/body=) ::
Invokes the hydra menu with short key bindings.
-Minibuffer editing is disabled when Hydra is active. Instead, you get
-short aliases for the common commands:
+When Hydra is active, minibuffer editing is disabled and menus
+display short aliases:
| Short | Normal | Command name |
|-------+-----------+---------------------------|
Hydra reduces key strokes, for example: ~C-n C-n C-n C-n~ is ~C-o
jjjj~ in Hydra.
-Additionally, you get access to the folowing commands that are
-normally not bound:
+Hydra menu offers these additioanl bindings:
- ~c~ (=ivy-toggle-calling=) ::
- Toggle calling the action after each candidate change. This
- effectively modifies ~j~ to ~jg~, ~k~ to ~kg~ etc.
+ Toggle calling the action after each candidate change. It
+ modifies ~j~ to ~jg~, ~k~ to ~kg~ etc.
- ~m~ (=ivy-toggle-fuzzy=) ::
Toggle the current regexp matcher.
Use a menu to select an action.
- ~C~ (=ivy-toggle-case-fold=) ::
- Toggle case folding (matching both upper and lower case
- characters with lower case input).
+ Toggle case folding (match both upper and lower case
+ characters for lower case input).
*** Saving the current completion session to a buffer
:PROPERTIES:
Ivy has no limit on the number of active buffers like these.
-Ivy takes care of making these buffer names unique. It applies
-descriptive names, for example: =*ivy-occur counsel-describe-variable
+Ivy takes care of naming buffers uniquely by constructing descriptive
+names. For example: =*ivy-occur counsel-describe-variable
"function$*=.
-* Completion styles
+* Completion Styles
:PROPERTIES:
:CUSTOM_ID: completion-styles
:END:
-Ivy's completion functions rely on the highly configurable regex
-builder.
+Ivy's completion functions rely on a regex builder - a function that
+transforms a string input to a string regex. All current candidates
+simply have to match this regex. Each collection can be assigned its
+own regex builder by customizing =ivy-re-builders-alist=.
+
+The keys of this alist are collection names, and the values are one of
+the following:
+- =ivy--regex=
+- =ivy--regex-plus=
+- =ivy--regex-ignore-order=
+- =ivy--regex-fuzzy=
+- =regexp-quote=
+
+A catch-all key, =t=, applies to all collections that don't have their
+own key.
The default is:
+
#+begin_src elisp
(setq ivy-re-builders-alist
'((t . ivy--regex-plus)))
#+end_src
-The default =ivy--regex-plus= narrowing is always invoked unless
-specified otherwise. For example, file name completion may have a
-custom completion function:
+This example shows a custom regex builder assigned to file name
+completion:
+
#+begin_src elisp
(setq ivy-re-builders-alist
'((read-file-name-internal . ivy--regex-fuzzy)
(t . ivy--regex-plus)))
#+end_src
-Ivy's flexibility extends to using different styles of completion
-mechanics (regex-builders) for different types of lists. Despite this
-flexibility, Ivy operates within a consistent and uniform interface.
-The main regex-builders currently in Ivy are:
+Here, =read-file-name-internal= is a function that is passed as the
+second argument to =completing-read= for file name completion.
+
+The regex builder resolves as follows (in order of priority):
+1. =re-builder= argument passed to =ivy-read=.
+2. =collection= argument passed to =ivy-read= is a function and has an
+ entry on =ivy-re-builders-alist=.
+3. =caller= argument passed to =ivy-read= has an entry on
+ =ivy-re-builders-alist=.
+4. =this-command= has an entry on =ivy-re-builders-alist=.
+5. =t= has an entry on =ivy-re-builders-alist=.
+6. =ivy--regex=.
** ivy--regex-plus
:PROPERTIES:
rebuilding it into a regex.
As the search string is typed in Ivy's minibuffer, it is transformed
-into proper regex syntax. If the string is ="for example"=, it is
+into valid regex syntax. If the string is ="for example"=, it is
transformed into
#+begin_src elisp
which in regex terminology matches ="for"= followed by a wild card and
then ="example"=. Note how Ivy uses the space character to build wild
-cards. For literal white space matching in Ivy, use an extra space: to
-match one space type two spaces, to match two spaces type three
-spaces, and so on.
+cards. To match a literal white space, use an extra space. So to match
+one space type two spaces, to match two spaces type three spaces, and
+so on.
As Ivy transforms typed characters into regex strings, it provides an
intuitive feedback through font highlights.
such large lists using =flx= package's scoring mechanism, if it's
installed.
+~C-o m~ toggles the current regexp builder.
+
+
+* Customization
+:PROPERTIES:
+:CUSTOM_ID: customization
+:END:
+** Faces
+:PROPERTIES:
+:CUSTOM_ID: faces
+:END:
+- =ivy-current-match= ::
+ Highlights the currently selected candidate.
+- =ivy-minibuffer-match-face-1= ::
+ Highlights the background of the match.
+- =ivy-minibuffer-match-face-2= ::
+ Highlights the first (modulo 3) matched group.
+- =ivy-minibuffer-match-face-3= ::
+ Highlights the second (modulo 3) matched group.
+- =ivy-minibuffer-match-face-4= ::
+ Highlights the third (modulo 3) matched group.
+- =ivy-confirm-face= ::
+ Highlights the "(confirm)" part of the prompt.
+
+ When =confirm-nonexistent-file-or-buffer= set to =t=, then
+ confirming non-existent files in =ivy-mode= requires an
+ additional ~RET~.
+
+ The confirmation prompt will use this face.
+
+ For example:
+
+ #+begin_src elisp
+ (setq confirm-nonexistent-file-or-buffer t)
+ #+end_src
+
+ Then call =find-file=, enter "eldorado" and press ~RET~ - the
+ prompt will be appended with "(confirm)". Press ~RET~ once more
+ to confirm, or any key to continue the completion.
+- =ivy-match-required-face= ::
+ Highlights the "(match required)" part of the prompt.
+
+ When completions have to match available candidates and cannot
+ take random input, the "(match required)" prompt signals this
+ constraint.
+
+ For example, call =describe-variable=, enter "waldo" and press
+ ~RET~ - "(match required)" is prompted.
+ Press any key for the prompt to disappear.
+- =ivy-subdir= ::
+ Highlights directories when completing file names.
+- =ivy-remote= ::
+ Highlights remote files when completing file names.
+- =ivy-virtual= ::
+ Highlights virtual buffers when completing buffer names.
+
+ Virtual buffers correspond to bookmarks and recent files list,
+ =recentf=.
+
+ Enable virtual buffers with:
+
+ #+begin_src elisp
+ (setq ivy-use-virtual-buffers t)
+ #+end_src
+** Defcustoms
+:PROPERTIES:
+:CUSTOM_ID: defcustoms
+:END:
+- User Option =ivy-count-format= ::
+ A string that specifies display of number of candidates and
+ current candidate, if one exists.
+
+ The number of matching candidates by default is shown as a right-
+ padded integer value.
+
+ To disable showing the number of candidates:
+
+ #+begin_src elisp
+ (setq ivy-count-format "")
+ #+end_src
+
+ To also display the current candidate:
+
+ #+begin_src elisp
+ (setq ivy-count-format "(%d/%d) ")
+ #+end_src
+
+ The =format=-style switches this variable uses are described
+ in the =format= documentation.
+
+- User Option =ivy-display-style= ::
+ Specifies highlighting candidates in the minibuffer.
+
+ The default setting is ='fancy= and valid only in Emacs versions
+ 24.5 or newer.
+
+ Set =ivy-display-style= to =nil= for a plain minibuffer.
+
+- User Option =ivy-on-del-error-function= ::
+ Specify what when ~DEL~ (=ivy-backward-delete-char=) throws.
+
+ The default behavior is to quit the completion after ~DEL~ -- a
+ handy key to invoke after mistakenly triggering a completion.
+
+** Actions
+:PROPERTIES:
+:CUSTOM_ID: actions
+:END:
+*** What are actions?
+:PROPERTIES:
+:CUSTOM_ID: what-are-actions
+:END:
+An action is a function that is called after you select a candidate
+during completion. This function takes a single string argument, which
+is the selected candidate.
+
+- Window context when calling an action ::
+ Currently, the action is executed in the minibuffer window
+ context. This means e.g. that if you call =insert= the text will
+ be inserted into the minibuffer.
+
+ If you want to execute the action in the initial window from
+ which the completion started, use the =with-ivy-window= wrapper
+ macro.
+
+ #+begin_src elisp
+ (defun ivy-insert-action (x)
+ (with-ivy-window
+ (insert x)))
+ #+end_src
+
+*** How can different actions be called?
+:PROPERTIES:
+:CUSTOM_ID: how-can-different-actions-be-called
+:END:
+- ~C-m~ (=ivy-done=) calls the current action.
+- ~M-o~ (=ivy-dispatching-done=) presents available actions for
+ selection, calls it after selection, and then exits.
+- ~C-M-o~ (=ivy-dispatching-call=) presents available actions for
+ selection, calls it after selection, and then does not exit.
+
+*** How to modify the actions list?
+:PROPERTIES:
+:CUSTOM_ID: how-to-modify-the-actions-list
+:END:
+Currently, you can append any amount of your own actions to the
+default list of actions. This can be done either for a specific
+command, or for all commands at once.
+
+Usually, the command has only one default action. The convention is to
+use single letters when selecting a command, and the letter ~o~ is
+designated for the default command. This way, ~M-o o~ should be always
+equivalent to ~C-m~.
+
+*** Example - add two actions to each command
+:PROPERTIES:
+:CUSTOM_ID: example---add-two-actions-to-each-command
+:END:
+The first action inserts the current candidate into the Ivy window -
+the window from which =ivy-read= was called.
+
+The second action copies the current candidate to the kill ring.
+
+#+begin_src elisp
+(defun ivy-yank-action (x)
+ (kill-new x))
+
+(defun ivy-copy-to-buffer-action (x)
+ (with-ivy-window
+ (insert x)))
+
+(ivy-set-actions
+ t
+ '(("i" ivy-copy-to-buffer-action "insert")
+ ("y" ivy-yank-action "yank")))
+#+end_src
+
+Then in any completion session, ~M-o y~ invokes =ivy-yank-action=, and
+~M-o i~ invokes =ivy-copy-to-buffer-action=.
+
+**** How to undo adding the two actions
+:PROPERTIES:
+:CUSTOM_ID: how-to-undo-adding-the-two-actions
+:END:
+Since =ivy-set-actions= modifies the internal dictionary with new
+data, set the extra actions list to =nil= by assigning =nil= value to
+the =t= key as follows:
+
+#+begin_src elisp
+(ivy-set-actions t nil)
+#+end_src
+
+**** How to add actions to a specific command
+:PROPERTIES:
+:CUSTOM_ID: how-to-add-actions-to-a-specific-command
+:END:
+Use the command name as the key:
+
+#+begin_src elisp
+(ivy-set-actions
+ 'swiper
+ '(("i" ivy-copy-to-buffer-action "insert")
+ ("y" ivy-yank-action "yank")))
+#+end_src
+
+*** Example - define a new command with several actions
+:PROPERTIES:
+:CUSTOM_ID: example---define-a-new-command-with-several-actions
+:END:
+#+begin_src elisp
+(defun my-action-1 (x)
+ (message "action-1: %s" x))
+
+(defun my-action-2 (x)
+ (message "action-2: %s" x))
+
+(defun my-action-3 (x)
+ (message "action-3: %s" x))
+
+(defun my-command-with-3-actions ()
+ (interactive)
+ (ivy-read "test: " '("foo" "bar" "baz")
+ :action '(1
+ ("o" my-action-1 "action 1")
+ ("j" my-action-2 "action 2")
+ ("k" my-action-3 "action 3"))))
+#+end_src
+
+The number 1 above is the index of the default action. Each
+action has its own string description for easy selection.
+
+**** Test the above function with =ivy-occur=
+:PROPERTIES:
+:CUSTOM_ID: test-the-above-function-with-ivy-occur
+:END:
+To examine each action with each candidate in a key-efficient way, try:
+
+- Call =my-command-with-3-actions=
+- Press ~C-c C-o~ to close the completion window and move to an
+ ivy-occur buffer
+- Press ~kkk~ to move to the first candidate, since the point is most
+ likely at the end of the buffer
+- Press ~oo~ to call the first action
+- Press ~oj~ and ~ok~ to call the second and the third actions
+- Press ~j~ to move to the next candidate
+- Press ~oo~, ~oj~, ~ok~
+- Press ~j~ to move to the next candidate
+- and so on...
+
+** Packages
+:PROPERTIES:
+:CUSTOM_ID: packages
+:END:
+- =org-mode= ::
+ =org-mode= versions 8.3.3 or later obey
+ =completing-read-function= (which =ivy-mode= sets). Try refiling
+ headings with similar names to appreciate =ivy-mode=.
+- =magit= ::
+ Magit requries this setting for ivy completion:
+
+ #+begin_src elisp
+ (setq magit-completing-read-function 'ivy-completing-read)
+ #+end_src
+- =find-file-in-project= ::
+ It uses ivy by default if Ivy is installed.
+- =projectile= ::
+ Projectile requires this seeting for ivy completion:
+
+ #+begin_src elisp
+ (setq projectile-completion-system 'ivy)
+ #+end_src
+- =helm-make= ::
+ Helm-make requires this seeting for ivy completion.
+
+ #+begin_src elisp
+ (setq helm-make-completion-method 'ivy)
+ #+end_src
+
+* Commands
+:PROPERTIES:
+:CUSTOM_ID: commands
+:END:
+** File Name Completion
+:PROPERTIES:
+:CUSTOM_ID: file-name-completion
+:END:
+Since file name completion is ubiquitious, Ivy provides extra
+bindings that work here:
+
+
+- ~C-j~ (=ivy-alt-done=) ::
+ On a directory, restarts completion from that directory.
+
+ On a file or =./=, exit completion with the selected candidate.
+- ~DEL~ (=ivy-backward-delete-char=) ::
+ Restart the completion in the parent directory if current input
+ is empty.
+- ~//~ (=self-insert-command=) ::
+ Switch to the root directory.
+- ~~~ (=self-insert-command=) ::
+ Switch to the home directory.
+- ~/~ (=self-insert-command=) ::
+ If the current input matches an existing directory name exactly,
+ switch the completion to that directory.
+- ~M-q~ (=ivy-toggle-regexp-quote=) ::
+ Toggle between input as regexp or not.
+
+ Switch to matching literally since file names include =.=, which
+ is for matching any char in regexp mode.
+
+- User Option =ivy-extra-directories= ::
+ Decide if you want to see =../= and =./= during file name
+ completion.
+
+ Reason to remove: =../= is the same as ~DEL~.
+
+ Reason not to remove: navigate anywhere with only ~C-n~, ~C-p~
+ and ~C-j~.
+
+ Likewise, =./= can be removed.
+
+- Using TRAMP ::
+ From any directory, with the empty input, inputting =/ssh:= and
+ pressing ~C-j~ (or ~RET~, which is the same thing) completes for
+ host and user names.
+
+ For =/ssh:user@= input, completes the domain name.
+
+ ~C-i~ works in a similar way to the default completion.
+
+- History ::
+ File history works the same with ~M-p~, ~M-n~, and ~C-r~, but
+ uses a custom code for file name completion that cycles through
+ files previously opened. It also works with TRAMP files.
+
+** Buffer Name Completion
+:PROPERTIES:
+:CUSTOM_ID: buffer-name-completion
+:END:
+- User Option =ivy-use-virtual-buffers= ::
+ When non-nil, add =recentf-mode= and bookmarks to
+ =ivy-switch-buffer= completion candidates.
+
+ Adding this to Emacs init file:
+
+ #+begin_src elisp
+ (setq ivy-use-virtual-buffers t)
+ #+end_src
+ will add additional virual buffers to the buffers list for recent
+ files. Selecting such virtual buffers, which are highlighted with
+ =ivy-virtual= face, will open the corresponding file.
+
+** Counsel commands
+:PROPERTIES:
+:CUSTOM_ID: counsel-commands
+:END:
+The main advantages of =counsel-= functions over their basic
+equivalents in =ivy-mode= are:
+
+1. Multi-actions and non-exiting actions work.
+2. =ivy-resume= can resume the last completion session.
+3. Customize =ivy-set-actions=, =ivy-re-builders-alist=.
+4. Customize individual keymaps, such as =counsel-describe-map=,
+ =counsel-git-grep-map=, or =counsel-find-file-map=, instead of
+ customizing =ivy-minibuffer-map= that applies to all completion
+ sessions.
+* API
+:PROPERTIES:
+:CUSTOM_ID: api
+:END:
+The main (and only) entry point is the =ivy-read= function. It takes
+two required arguments and many optional arguments that can be passed
+by a key. The optional =:action= argument is highly recommended for
+features such as multi-actions, non-exiting actions, =ivy-occur= and
+=ivy-resume=.
+
+** Required arguments for =ivy-read=
+:PROPERTIES:
+:CUSTOM_ID: required-arguments-for-ivy-read
+:END:
+- =prompt= ::
+ A format string normally ending in a colon and a space.
+
+ =%d= anywhere in the string is replaced by the current number of
+ matching candidates. To use a literal =%= character, escape it as
+ =%%=. See also =ivy-count-format=.
+
+- =collection= ::
+ Either a list of strings, a function, an alist or a hash table.
+
+ If a function, then it has to be compatible with
+ =all-completions=.
+
+** Optional arguments for =ivy-read=
+:PROPERTIES:
+:CUSTOM_ID: optional-arguments-for-ivy-read
+:END:
+- =predicate= ::
+ Is a function to filter the initial collection. It has to be
+ compatible with =all-completions=. Tip: most of the time, it's
+ simpler to just apply this filter to the =collection= argument
+ itself, e.g. =(cl-remove-if-not predicate collection)=.
+- =require-match= ::
+ When set to a non-nil value, input must match one of the
+ candidates. Custom input is not accepted.
+- =initial-input= ::
+ This string argument is included for compatibility with
+ =completing-read=, which inserts it into the minibuffer.
+
+ It's recommended to use the =preselect= argument instead of this.
+- =history= ::
+ Name of the symbol to store history. See =completing-read=.
+- =preselect= ::
+ When set to a string value, select the first candidate matching
+ this value.
+
+ When set to an integer value, select the candidate with that
+ index value.
+
+ Every time the input becomes empty, the item corresponding to to
+ =preselect= is selected.
+- =keymap= ::
+ A keymap to be composed with =ivy-minibuffer-map=. This keymap
+ has priority over =ivy-minibuffer-map= and can be modified at any
+ later stage.
+- =update-fn= ::
+ Is the function called each time the current candidate changes.
+ This function takes no arguments and is called in the
+ minibuffer's =post-command-hook=. See =swiper= for an example
+ usage.
+- =sort= ::
+ When non-nil, use =ivy-sort-functions-alist= to sort the
+ collection as long as the collection is not larger than
+ =ivy-sort-max-size=.
+- =action= ::
+ Is the function to call after selection. It takes a string
+ argument.
+- =unwind= ::
+ Is the function to call before exiting completion. It takes no
+ arguments. This function is called even if the completion is
+ interrupted with ~C-g~. See =swiper= for an example usage.
+- =re-builder= ::
+ Is a function that takes a string and returns a valid regex. See
+ =Completion Styles= for details.
+- =matcher= ::
+ Is a function that takes a regex string and a list of strings and
+ returns a list of strings matching the regex. Any ordinary Emacs
+ matching function will suffice, yet finely tuned mathing
+ functions can be used. See =counsel-find-file= for an example
+ usage.
+- =dynamic-collection= ::
+ When non-nil, =collection= will be used to dynamically generate
+ the candidates each time the input changes, instead of being used
+ once statically with =all-completions= to generate a list of
+ strings. See =counsel-locate= for an example usage.
+- =caller= ::
+ Is a symbol that uniquely identifies the function that called
+ =ivy-read=, which may be useful for further customizations.
+** Example - =counsel-describe-function=
+:PROPERTIES:
+:CUSTOM_ID: example---counsel-describe-function
+:END:
+This is a typical example of a function with a non-async collection,
+which is a collection where all the strings in the collection are
+known prior to any input from the user.
+
+Only the first two arguments (along with =action=) are essential - the
+rest of the arguments are for fine-tuning, and could be omitted.
+
+The =action= argument could also be omitted - but then =ivy-read=
+would do nothing except returning the string result, which you could
+later use yourself. However, it's recommended that you use the
+=action= argument.
+
+#+begin_src elisp
+(defun counsel-describe-function ()
+ "Forward to `describe-function'."
+ (interactive)
+ (ivy-read "Describe function: "
+ (let (cands)
+ (mapatoms
+ (lambda (x)
+ (when (fboundp x)
+ (push (symbol-name x) cands))))
+ cands)
+ :keymap counsel-describe-map
+ :preselect (counsel-symbol-at-point)
+ :history 'counsel-describe-symbol-history
+ :require-match t
+ :sort t
+ :action (lambda (x)
+ (describe-function
+ (intern x)))
+ :caller 'counsel-describe-function))
+#+end_src
+
+Here are the interesting features of the above function, in the order that they appear:
+
+- The =prompt= argument is a simple string ending in ": ".
+- The =collection= argument evaluates to a (large) list of strings.
+- The =keymap= argument is for a custom keymap to supplement =ivy-minibuffer-map=.
+- The =preselect= is provided by =counsel-symbol-at-point=, which
+ returns a symbol near the point. Ivy then selects the first
+ candidate from the collection that matches this symbol. To select
+ this pre-selected candidate, a ~RET~ will suffice. No further user
+ input is necessary.
+- The =history= argument is for keeping the history of this command
+ separate from the common history in =ivy-history=.
+- The =require-match= is set to =t= since it doesn't make sense to
+ call =describe-function= on an un-interned symbol.
+- The =sort= argument is set to =t= so choosing between similar
+ candidates becomes easier. Sometimes, the collection size will
+ exceed =ivy-sort-max-size=, which is 30000 by default. In that case
+ the sorting will not happen to avoid delays.
+
+ Adjust this variable to choose between sorting time and completion
+ start-up time.
+- The =action= argument calls =describe-function= on the interned
+ selected candidate.
+- The =caller= argument identifies this completion session. This is
+ important, since with the collection being a list of strings and not
+ a function name, the only other way for =ivy-read= to identify
+ "who's calling" and to apply the appropriate customizations is to
+ examine =this-command=. But =this-command= would be modified if
+ another command called =counsel-describe-function=.
+** Example - =counsel-locate=
+:PROPERTIES:
+:CUSTOM_ID: example---counsel-locate
+:END:
+This is a typical example of a function with an async collection.
+Since the collection function cannot pre-compute all the locatable
+files in memory within reasonable limits (time or memory), it relies
+on user input to filter the universe of possible candidates to a
+manageable size while also continuing to search asynchronously for
+possible candidates. Both the filtering and searching continues with
+each character change of the input with rapid updates to the
+collection presented without idle waiting times. This live update will
+continue as long as there are likely candidates. Eventually updates to
+the minibuffer will stop after user input, filtering, and searching
+have exhausted looking for possible candidates.
+
+Async collections suit long-running shell commands, such as =locate=.
+With each new input, a new process starts while the old process is
+killed. The collection is refreshed anew with each new process.
+Meanwhile the user can provide more input characters (for further
+narrowing) or select a candidate from the visible collection.
+
+#+begin_src elisp
+(defun counsel-locate-function (str)
+ (if (< (length str) 3)
+ (counsel-more-chars 3)
+ (counsel--async-command
+ (format "locate %s '%s'"
+ (mapconcat #'identity counsel-locate-options " ")
+ (counsel-unquote-regex-parens
+ (ivy--regex str))))
+ '("" "working...")))
+
+;;;###autoload
+(defun counsel-locate (&optional initial-input)
+ "Call the \"locate\" shell command.
+INITIAL-INPUT can be given as the initial minibuffer input."
+ (interactive)
+ (ivy-read "Locate: " #'counsel-locate-function
+ :initial-input initial-input
+ :dynamic-collection t
+ :history 'counsel-locate-history
+ :action (lambda (file)
+ (with-ivy-window
+ (when file
+ (find-file file))))
+ :unwind #'counsel-delete-process
+ :caller 'counsel-locate))
+#+end_src
+
+Here are the interesting features of the above functions, in the order
+that they appear:
+
+- =counsel-locate-function= takes a string argument and returns a list
+ of strings. Note that it's not compatible with =all-completions=,
+ but since we're not using that here, might as well use one argument
+ instead of three.
+- =counsel-more-chars= is a simple function that returns e.g.
+ ='("2 chars more")= asking the user for more input.
+- =counsel--async-command= is a very easy API simplification that
+ takes a single string argument suitable for
+ =shell-command-to-string=. So you could prototype your function as
+ non-async using =shell-command-to-string= and =split-string= to
+ produce a collection, then decide that you want async and simply swap in
+ =counsel--async-command=.
+- =counsel-locate= is an interactive function with an optional =initial-input=.
+- =#'counsel-locate-function= is passed as the =collection= argument.
+- =dynamic-collection= is set to t, since this is an async collection.
+- =action= argument uses =with-ivy-window= wrapper, since we want to open the
+ selected file in the same window from which =counsel-locate= was
+ called.
+- =unwind= argument is set to =#'counsel-delete-process=: when we press ~C-g~
+ we want to kill the running process created by
+ =counsel--async-command=.
+- =caller= argument identifies this command for easier customization.
+
* Variable Index
:PROPERTIES:
:INDEX: vr
:CUSTOM_ID: variable-index
:END:
+
+* Keystroke Index
+:PROPERTIES:
+:CUSTOM_ID: key-index
+:INDEX: ky
+:END: