━━━━━━━━━━━ ORDERLESS ━━━━━━━━━━━ 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 (see the external [icomplete-vertical] package to get that functionality on earlier versions of Emacs), or with some third party minibuffer completion frameworks such as [Mct], [Vertico], or [Selectrum] (in its default configuration). 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], [Company] or the function `consult-completion-in-region' from [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' (see their documentation). You may also want to modify the `completion-category-defaults' variable, which serves as a default value for `completion-category-overrides': if you want to use `orderless' exclusively, set both variables to `nil'. 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] (see 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 basic partial-completion))))) └──── 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 basic 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. 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! [icomplete-vertical] [Mct] [Vertico] [Selectrum] [Corfu] [Company] [Consult] [Ivy] 2 Customization ═══════════════ 2.1 Component matching styles ───────────────────────────── Each component of a pattern can match in any of several matching styles. A matching style is simply a function from strings to strings that maps a component to a regexp to match against, so it is easy to define new matching styles. The predefined ones 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. This is just `regexp-quote'. *orderless-without-literal* the component is a treated as a literal string that must *not* occur in the candidate. Note that nothing is highlighted for this matching style. You probably don't want to use this style directly in `orderless-matching-styles' but with a style dispatcher instead. There is an example in the section on style dispatchers. 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 `\ 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. 2.5 Pattern compiler ──────────────────── The default mechanism for turning an input string into 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 the `orderless-pattern-compiler'. Under special circumstances it may be useful to implement a custom pattern compiler by advising the `orderless-pattern-compiler'. 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] 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. [hydra] 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. 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)) └──── 3.2 Helm ──────── To use `orderless' from Helm, simply configure `orderless' as you would for completion UIs that use Emacs completion stlyes and add this to your Helm configuration: ┌──── │ (setq helm-completion-style 'emacs) └──── 3.3 Selectrum ───────────── Recent versions of Selectrum default to using whatever completion styles you have configured. If you stick with that default configuration you can use `orderless' just by adding it to `completion-styles'. Alternatively, you can use this configuration: ┌──── │ (setq selectrum-refine-candidates-function #'orderless-filter) │ (setq selectrum-highlight-candidates-function #'orderless-highlight-matches) └──── If you use the above configuration, only the visible candidates are highlighted, which is a litte more efficient. Note that Selectrum has been deprecated in favor of Vertico. 3.4 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 config: ┌──── │ ;; 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) └──── 4 Related packages ══════════════════ 4.1 Ivy and Helm ──────────────── The well-known and hugely powerful completion frameworks [Ivy] and [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, Selectrum 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.) [Ivy] [Helm] 4.2 Prescient ───────────── The [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 Selectrum and Ivy are 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. [prescient.el] 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] 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'. [Icicles]