This is orderless.info, produced by makeinfo version 7.1.1 from
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INFO-DIR-SECTION Emacs misc features
START-INFO-DIR-ENTRY
* Orderless: (orderless). Completion style for matching regexps in any order.
END-INFO-DIR-ENTRY


File: orderless.info,  Node: Top,  Next: Overview,  Up: (dir)

Orderless
*********

* Menu:

* Overview::
* Customization::
* Integration with other completion UIs::
* Related packages::

-- The Detailed Node Listing --

Customization

* Component matching styles::
* Component separator regexp::
* Defining custom orderless styles::
* Faces for component matches::
* Pattern compiler::
* Interactively changing the configuration::

Component matching styles

* Style modifiers::
* Style dispatchers::

Integration with other completion UIs

* Ivy::
* Helm::
* Company::

Related packages

* Ivy and Helm::
* Prescient::
* Restricting to current matches in Icicles, Ido and Ivy::



File: orderless.info,  Node: Overview,  Next: Customization,  Prev: Top,  Up: Top

1 Overview
**********

This package provides an ‘orderless’ _completion style_ that divides the
pattern into space-separated components, and matches candidates that
match all of the components in any order.  Each component can match in
any one of several ways: literally, as a regexp, as an initialism, in
the flex style, or as multiple word prefixes.  By default, regexp and
literal matches are enabled.

   A completion style is a back-end for completion and is used from a
front-end that provides a completion UI.  Any completion style can be
used with the default Emacs completion UI (sometimes called minibuffer
tab completion), with the built-in Icomplete package (which is similar
to the more well-known Ido Mode), the icomplete-vertical variant from
Emacs 28, or with minibuffer completion frameworks such as Mct
(https://gitlab.com/protesilaos/mct) or Vertico
(https://github.com/minad/vertico).

   All the completion UIs just mentioned are for minibuffer completion,
used when Emacs commands prompt the user in the minibuffer for some
input, but there is also completion at point in normal buffers,
typically used for identifiers in programming languages.  Completion
styles can also be used for that purpose by completion at point UIs such
as Corfu (https://github.com/minad/corfu), Company
(https://company-mode.github.io/) or the function
‘consult-completion-in-region’ from Consult
(https://github.com/minad/consult).

   To use a completion style with any of the above mentioned completion
UIs simply add it as an entry in the variables ‘completion-styles’ and
‘completion-category-overrides’ and ‘completion-category-defaults’ (see
their documentation).

   The ‘completion-category-defaults’ variable serves as a default value
for ‘completion-category-overrides’.  If you want to use ‘orderless’
exclusively, set both variables to ‘nil’, but be aware that
‘completion-category-defaults’ is modified by packages at load time.

   With a bit of effort, it might still be possible to use ‘orderless’
with other completion UIs, even if those UIs don't support the standard
Emacs completion styles.  Currently there is support for Ivy
(https://github.com/abo-abo/swiper), as documented below.  Also, while
Company does support completion styles directly, pressing ‘SPC’ takes
you out of completion, so comfortably using ‘orderless’ with it takes a
bit of configuration (see below).

   If you use ELPA or MELPA, the easiest way to install ‘orderless’ is
via ‘package-install’.  If you use ‘use-package’, you can use:

     (use-package orderless
       :ensure t
       :custom
       (completion-styles '(orderless basic))
       (completion-category-overrides '((file (styles partial-completion))))
       (completion-pcm-leading-wildcard t)) ;; Emacs 31: partial-completion behaves like substring

   Alternatively, put ‘orderless.el’ somewhere on your ‘load-path’, and
use the following configuration:

     (require 'orderless)
     (setq completion-styles '(orderless basic)
           completion-category-overrides '((file (styles partial-completion)))
           completion-pcm-leading-wildcard t) ;; Emacs 31: partial-completion behaves like substring

   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.  Furthermore the ‘basic’
completion style needs to be tried _first_ (not as a fallback) for TRAMP
hostname completion to work.  In order to achieve that, we add an entry
for the ‘file’ completion category in the
‘completion-category-overrides’ variable.  In addition, the
‘partial-completion’ style allows you to use wildcards for file
completion and partial paths, e.g., ‘/u/s/l’ for ‘/usr/share/local’.

   Bug reports are highly welcome and appreciated!


File: orderless.info,  Node: Customization,  Next: Integration with other completion UIs,  Prev: Overview,  Up: Top

2 Customization
***************

* Menu:

* Component matching styles::
* Component separator regexp::
* Defining custom orderless styles::
* Faces for component matches::
* Pattern compiler::
* Interactively changing the configuration::


File: orderless.info,  Node: Component matching styles,  Next: Component separator regexp,  Up: Customization

2.1 Component matching styles
=============================

Each component of a pattern can match in any of several matching styles.
A matching style is a function from strings to regexps or predicates, so
it is easy to define new matching styles.  The value returned by a
matching style can be either a regexp as a string, an s-expression in
‘rx’ syntax or a predicate function.  The predefined matching styles
are:

orderless-regexp
     the component is treated as a regexp that must match somewhere in
     the candidate.

     If the component is not a valid regexp, it is ignored.

orderless-literal
     the component is treated as a literal string that must occur in the
     candidate.

orderless-literal-prefix
     the component is treated as a literal string that must occur as a
     prefix of a candidate.

orderless-prefixes
     the component is split at word endings and each piece must match at
     a word boundary in the candidate, occurring in that order.

     This is similar to the built-in ‘partial-completion’
     completion-style.  For example, ‘re-re’ matches
     ‘query-replace-regexp’, ‘recode-region’ and
     ‘magit-remote-list-refs’; ‘f-d.t’ matches ‘final-draft.txt’.

orderless-initialism
     each character of the component should appear as the beginning of a
     word in the candidate, in order.

     This maps ‘abc’ to ‘\<a.*\<b.*\c’.

orderless-flex
     the characters of the component should appear in that order in the
     candidate, but not necessarily consecutively.

     This maps ‘abc’ to ‘a.*b.*c’.

*orderless-without-literal*
     the component is a treated as a literal string that must *not*
     occur in the candidate.

     Nothing is highlighted by this style.  This style should not be
     used directly in ‘orderless-matching-styles’ but with a style
     dispatcher instead.  See also the more general style modifier
     ‘orderless-not’.

   The variable ‘orderless-matching-styles’ can be set to a list of the
desired matching styles to use.  By default it enables the literal and
regexp styles.

* Menu:

* Style modifiers::
* Style dispatchers::


File: orderless.info,  Node: Style modifiers,  Next: Style dispatchers,  Up: Component matching styles

2.1.1 Style modifiers
---------------------

Style modifiers are functions which take a predicate function and a
regular expression as a string and return a new predicate function.
Style modifiers should not be used directly in
‘orderless-matching-styles’ but with a style dispatcher instead.

orderless-annotation
     this style modifier matches the pattern against the annotation
     string of the candidate, instead of against the candidate string.

orderless-not
     this style modifier inverts the pattern, such that candidates pass
     which do not match the pattern.


File: orderless.info,  Node: Style dispatchers,  Prev: Style modifiers,  Up: Component matching styles

2.1.2 Style dispatchers
-----------------------

For more fine-grained control on which matching styles to use for each
component of the input string, you can customize the variable
‘orderless-style-dispatchers’.  You can use this feature to define your
own "query syntax".  For example, the default value of
‘orderless-style-dispatchers’ lists a single dispatcher called
‘orderless-affix-dispatch’ which enables a simple syntax based on
special characters used as either a prefix or suffix:

   • !  modifies the component with ‘orderless-not’.  Both ‘!bad’ and
     ‘bad!’ will match strings that do _not_ contain the pattern ‘bad’.
   • & modifies the component with ‘orderless-annotation’.  The pattern
     will match against the candidate's annotation (cheesy mnemonic:
     andnotation!).
   • , uses ‘orderless-initialism’.
   • = uses ‘orderless-literal’.
   • ^ uses ‘orderless-literal-prefix’.
   • ~ uses ‘orderless-flex’.
   • % makes the string match ignoring diacritics and similar
     inflections on characters (it uses the function
     ‘char-fold-to-regexp’ to do this).

   You can add, remove or change this mapping between affix characters
and matching styles by customizing the user option
‘orderless-affix-dispatch-alist’.  Most users will probably find this
type of customization sufficient for their query syntax needs, but for
those desiring further control the rest of this section explains how to
implement your own style dispatchers.

   Style dispatchers are functions which take a component, its index in
the list of components (starting from 0), and the total number of
components, and are used to determine the matching styles used for that
specific component, overriding the default matching styles.

   A style dispatcher can either decline to handle the input string or
component, or it can return which matching styles to use.  It can also,
if desired, additionally return a new string to use in place of the
given one.  Consult the documentation of ‘orderless--dispatch’ for full
details.

   As an example of writing your own dispatchers, say you wanted the
following setup:

   • you normally want components to match as regexps,
   • except for the first component, which should always match as an
     initialism --this is pretty useful for, say,
     ‘execute-extended-command’ (‘M-x’) or ‘describe-function’ (‘C-h
     f’),
   • later components ending in ‘~’ should match (the characters other
     than the final ‘~’) in the flex style, and
   • later components starting with ‘!’ should indicate the rest of the
     component is a literal string not contained in the candidate (this
     is part of the functionality of the default configuration).

   You can achieve this with the following configuration:

     (defun flex-if-twiddle (pattern _index _total)
       (when (string-suffix-p "~" pattern)
         `(orderless-flex . ,(substring pattern 0 -1))))

     (defun first-initialism (pattern index _total)
       (if (= index 0) 'orderless-initialism))

     (defun not-if-bang (pattern _index _total)
       (cond
        ((equal "!" pattern)
         #'ignore)
        ((string-prefix-p "!" pattern)
         `(orderless-not . ,(substring pattern 1)))))

     (setq orderless-matching-styles '(orderless-regexp)
           orderless-style-dispatchers '(first-initialism
                                         flex-if-twiddle
                                         not-if-bang))


File: orderless.info,  Node: Component separator regexp,  Next: Defining custom orderless styles,  Prev: Component matching styles,  Up: Customization

2.2 Component separator regexp
==============================

The pattern components are space-separated by default: this is
controlled by the variable ‘orderless-component-separator’, which should
be set either to a regexp that matches the desired component separator,
or to a function that takes a string and returns the list of components.
The default value is a regexp matches a non-empty sequence of spaces.
It may be useful to add hyphens or slashes (or both), to match symbols
or file paths, respectively.

   Even if you want to split on spaces you might want to be able to
escape those spaces or to enclose space in double quotes (as in shell
argument parsing).  For backslash-escaped spaces set
‘orderless-component-separator’ to the function
‘orderless-escapable-split’; for shell-like double-quotable space, set
it to the standard Emacs function ‘split-string-and-unquote’.

   If you are implementing a command for which you know you want a
different separator for the components, bind
‘orderless-component-separator’ in a ‘let’ form.


File: orderless.info,  Node: Defining custom orderless styles,  Next: Faces for component matches,  Prev: Component separator regexp,  Up: Customization

2.3 Defining custom orderless styles
====================================

Orderless allows the definition of custom completion styles using the
‘orderless-define-completion-style’ macro.  Any Orderless configuration
variable can be adjusted locally for the new style, e.g.,
‘orderless-matching-styles’.

   By default Orderless only enables the regexp and literal matching
styles.  In the following example an ‘orderless+initialism’ style is
defined, which additionally enables initialism matching.  This
completion style can then used when matching candidates of the symbol or
command completion category.

     (orderless-define-completion-style orderless+initialism
       (orderless-matching-styles '(orderless-initialism
                                    orderless-literal
                                    orderless-regexp)))
     (setq completion-category-overrides
           '((command (styles orderless+initialism))
             (symbol (styles orderless+initialism))
             (variable (styles orderless+initialism))))

   Note that in order for the ‘orderless+initialism’ style to kick-in
with the above configuration, you'd need to use commands whose metadata
indicates that the completion candidates are commands or symbols.  In
Emacs 28, ‘execute-extended-command’ has metadata indicating you are
selecting a command, but earlier versions of Emacs lack this metadata.
Activating ‘marginalia-mode’ from the Marginalia
(https://github.com/minad/marginalia) package provides this metadata
automatically for many built-in commands and is recommended if you use
the above example configuration, or other similarly fine-grained control
of completion styles according to completion category.


File: orderless.info,  Node: Faces for component matches,  Next: Pattern compiler,  Prev: Defining custom orderless styles,  Up: Customization

2.4 Faces for component matches
===============================

The portions of a candidate matching each component get highlighted in
one of four faces, ‘orderless-match-face-?’ where ‘?’ is a number from 0
to 3.  If the pattern has more than four components, the faces get
reused cyclically.

   If your ‘completion-styles’ (or ‘completion-category-overrides’ for
some particular category) has more than one entry, remember than Emacs
tries each completion style in turn and uses the first one returning
matches.  You will only see these particular faces when the ‘orderless’
completion is the one that ends up being used, of course.


File: orderless.info,  Node: Pattern compiler,  Next: Interactively changing the configuration,  Prev: Faces for component matches,  Up: Customization

2.5 Pattern compiler
====================

The default mechanism for turning an input string into a predicate and a
list of regexps to match against, configured using
‘orderless-matching-styles’, is probably flexible enough for the vast
majority of users.  The patterns are compiled by ‘orderless-compile’.
Under special circumstances it may be useful to implement a custom
pattern compiler by advising ‘orderless-compile’.


File: orderless.info,  Node: Interactively changing the configuration,  Prev: Pattern compiler,  Up: Customization

2.6 Interactively changing the configuration
============================================

You might want to change the separator or the matching style
configuration on the fly while matching.  There many possible user
interfaces for this: you could toggle between two chosen configurations,
cycle among several, have a keymap where each key sets a different
configurations, have a set of named configurations and be prompted (with
completion) for one of them, popup a hydra
(https://github.com/abo-abo/hydra) to choose a configuration, etc.
Since there are so many possible UIs and which to use is mostly a matter
of taste, ‘orderless’ does not provide any such commands.  But it's easy
to write your own!

   For example, say you want to use the keybinding ‘C-l’ to make all
components match literally.  You could use the following code:

     (defun my/match-components-literally ()
       "Components match literally for the rest of the session."
       (interactive)
       (setq-local orderless-matching-styles '(orderless-literal)
                   orderless-style-dispatchers nil))

     (define-key minibuffer-local-completion-map (kbd "C-l")
       #'my/match-components-literally)

   Using ‘setq-local’ to assign to the configuration variables ensures
the values are only used for that minibuffer completion session.


File: orderless.info,  Node: Integration with other completion UIs,  Next: Related packages,  Prev: Customization,  Up: Top

3 Integration with other completion UIs
***************************************

Several excellent completion UIs exist for Emacs in third party
packages.  They do have a tendency to forsake standard Emacs APIs, so
integration with them must be done on a case by case basis.

   If you manage to use ‘orderless’ with a completion UI not listed
here, please file an issue or make a pull request so others can benefit
from your effort.  The functions ‘orderless-filter’,
‘orderless-highlight-matches’, ‘orderless--highlight’ and
‘orderless--component-regexps’ are likely to help with the integration.

* Menu:

* Ivy::
* Helm::
* Company::


File: orderless.info,  Node: Ivy,  Next: Helm,  Up: Integration with other completion UIs

3.1 Ivy
=======

To use ‘orderless’ from Ivy add this to your Ivy configuration:

     (setq ivy-re-builders-alist '((t . orderless-ivy-re-builder)))
     (add-to-list 'ivy-highlight-functions-alist '(orderless-ivy-re-builder . orderless-ivy-highlight))


File: orderless.info,  Node: Helm,  Next: Company,  Prev: Ivy,  Up: Integration with other completion UIs

3.2 Helm
========

To use ‘orderless’ from Helm, simply configure ‘orderless’ as you would
for completion UIs that use Emacs completion styles and add this to your
Helm configuration:

     (setq helm-completion-style 'emacs)


File: orderless.info,  Node: Company,  Prev: Helm,  Up: Integration with other completion UIs

3.3 Company
===========

Company comes with a ‘company-capf’ backend that uses the
completion-at-point functions, which in turn use completion styles.
This means that the ‘company-capf’ backend will automatically use
‘orderless’, no configuration necessary!

   But there are a couple of points of discomfort:

  1. Pressing SPC takes you out of completion, so with the default
     separator you are limited to one component, which is no fun.  To
     fix this add a separator that is allowed to occur in identifiers,
     for example, for Emacs Lisp code you could use an ampersand:

          (setq orderless-component-separator "[ &]")

  2. The matching portions of candidates aren't highlighted.  That's
     because ‘company-capf’ is hard-coded to look for the
     ‘completions-common-part’ face, and it only use one face,
     ‘company-echo-common’ to highlight candidates.

     So, while you can't get different faces for different components,
     you can at least get the matches highlighted in the sole available
     face with this configuration:

          (defun just-one-face (fn &rest args)
            (let ((orderless-match-faces [completions-common-part]))
              (apply fn args)))

          (advice-add 'company-capf--candidates :around #'just-one-face)

     (Aren't dynamically scoped variables and the advice system nifty?)

   If you would like to use different ‘completion-styles’ with
‘company-capf’ instead, you can add this to your configuration:

     ;; We follow a suggestion by company maintainer u/hvis:
     ;; https://www.reddit.com/r/emacs/comments/nichkl/comment/gz1jr3s/
     (defun company-completion-styles (capf-fn &rest args)
       (let ((completion-styles '(basic partial-completion)))
         (apply capf-fn args))

     (advice-add 'company-capf :around #'company-completion-styles)


File: orderless.info,  Node: Related packages,  Prev: Integration with other completion UIs,  Up: Top

4 Related packages
******************

* Menu:

* Ivy and Helm::
* Prescient::
* Restricting to current matches in Icicles, Ido and Ivy::


File: orderless.info,  Node: Ivy and Helm,  Next: Prescient,  Up: Related packages

4.1 Ivy and Helm
================

The well-known and hugely powerful completion frameworks Ivy
(https://github.com/abo-abo/swiper) and Helm
(https://github.com/emacs-helm/helm) also provide for matching
space-separated component regexps in any order.  In Ivy, this is done
with the ‘ivy--regex-ignore-order’ matcher.  In Helm, it is the default,
called "multi pattern matching".

   This package is significantly smaller than either of those because it
solely defines a completion style, meant to be used with any completion
UI supporting completion styles while both of those provide their own
completion UI (and many other cool features!).

   It is worth pointing out that Helm does provide its multi pattern
matching as a completion style which could be used with default tab
completion, Icomplete or other UIs supporting completion styles!  (Ivy
does not provide a completion style to my knowledge.)  So, for example,
Icomplete users could, instead of using this package, install Helm and
configure Icomplete to use it as follows:

     (require 'helm)
     (setq completion-styles '(helm basic))
     (icomplete-mode)

   (Of course, if you install Helm, you might as well use the Helm UI in
‘helm-mode’ rather than Icomplete.)


File: orderless.info,  Node: Prescient,  Next: Restricting to current matches in Icicles, Ido and Ivy,  Prev: Ivy and Helm,  Up: Related packages

4.2 Prescient
=============

The prescient.el (https://github.com/radian-software/prescient.el)
library also provides matching of space-separated components in any
order.  It offers a completion-style that can be used with Emacs'
default completion UI, Mct, Vertico or with Icomplete.  Furthermore Ivy
is supported.  The components can be matched literally, as regexps, as
initialisms or in the flex style (called "fuzzy" in prescient).
Prescient does not offer the same flexibility as Orderless with its
style dispatchers.  However in addition to matching, Prescient supports
sorting of candidates, while Orderless leaves that up to the candidate
source and the completion UI.


File: orderless.info,  Node: Restricting to current matches in Icicles, Ido and Ivy,  Prev: Prescient,  Up: Related packages

4.3 Restricting to current matches in Icicles, Ido and Ivy
==========================================================

An effect equivalent to matching multiple components in any order can be
achieved in completion frameworks that provide a way to restrict further
matching to the current list of candidates.  If you use the keybinding
for restriction instead of ‘SPC’ to separate your components, you get
out of order matching!

   • Icicles (https://www.emacswiki.org/emacs/Icicles) calls this
     _progressive completion_ and uses the
     ‘icicle-apropos-complete-and-narrow’ command, bound to ‘S-SPC’, to
     do it.

   • Ido has ‘ido-restrict-to-matches’ and binds it to ‘C-SPC’.

   • Ivy has ‘ivy-restrict-to-matches’, bound to ‘S-SPC’, so you can get
     the effect of out of order matching without using
     ‘ivy--regex-ignore-order’.



Tag Table:
Node: Top237
Node: Overview921
Node: Customization5000
Node: Component matching styles5358
Node: Style modifiers7649
Node: Style dispatchers8338
Node: Component separator regexp11995
Node: Defining custom orderless styles13223
Node: Faces for component matches15113
Node: Pattern compiler15917
Node: Interactively changing the configuration16508
Node: Integration with other completion UIs17969
Node: Ivy18755
Node: Helm19107
Node: Company19451
Node: Related packages21422
Node: Ivy and Helm21666
Node: Prescient22996
Node: Restricting to current matches in Icicles, Ido and Ivy23826

End Tag Table


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