GNU ELPA - marginalia

marginalia

Description
Enrich existing commands with completion annotations
Latest
marginalia-0.8.tar, 2021-Aug-11, 220 KiB
Maintainer
Omar Antolín Camarena <omar@matem.unam.mx>, Daniel Mendler <mail@daniel-mendler.de>
Home page
https://github.com/minad/marginalia
Browse ELPA's repository
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To install this package, run in Emacs:

M-x package-install RET marginalia RET

Full description

#+title: marginalia.el - Marginalia in the minibuffer
#+author: Omar Antolín Camarena, Daniel Mendler
#+language: en
#+export_file_name: marginalia.texi
#+texinfo_dir_category: Emacs
#+texinfo_dir_title: Marginalia: (marginalia).
#+texinfo_dir_desc: Marginalia in the minibuffer

#+html: <a href="http://elpa.gnu.org/packages/marginalia.html"><img alt="GNU ELPA" src="https://elpa.gnu.org/packages/marginalia.svg"/></a>
#+html: <a href="http://elpa.gnu.org/devel/marginalia.html"><img alt="GNU-devel ELPA" src="https://elpa.gnu.org/devel/marginalia.svg"/></a>
#+html: <a href="https://melpa.org/#/marginalia"><img alt="MELPA" src="https://melpa.org/packages/marginalia-badge.svg"/></a>
#+html: <a href="https://stable.melpa.org/#/marginalia"><img alt="MELPA Stable" src="https://stable.melpa.org/packages/marginalia-badge.svg"/></a>

* Introduction

#+html: <img src="https://upload.wikimedia.org/wikipedia/commons/4/4f/Marginalia_%285095211566%29.jpg" align="right" width="30%">

This package provides =marginalia-mode= which adds marginalia to the
minibuffer completions.
[[https://en.wikipedia.org/wiki/Marginalia][Marginalia]] are marks or
annotations placed at the margin of the page of a book or in this case
helpful colorful annotations placed at the margin of the minibuffer for
your completion candidates. Marginalia can only add annotations to be
displayed with the completion candidates. It cannot modify the
appearance of the candidates themselves, which are shown as supplied by
the original commands.

The annotations are added based on the completion category. For example
=find-file= reports the =file= category and =M-x= reports the =command= category. You
can cycle between more or less detailed annotators or even disable the annotator
with command =marginalia-cycle=.

#+html: <img src="https://github.com/minad/marginalia/blob/main/marginalia-mode.png?raw=true">

* Configuration

It is recommended to use Marginalia together with either the [[https://github.com/raxod502/selectrum][Selectrum]], [[https://github.com/minad/vertico][Vertico]]
or the [[https://github.com/oantolin/icomplete-vertical][Icomplete-vertical]] completion system. Furthermore Marginalia can be
combined with [[https://github.com/oantolin/embark][Embark]] for action support and [[https://github.com/minad/consult][Consult]], which provides many useful
commands.

#+begin_src emacs-lisp
;; Enable richer annotations using the Marginalia package
(use-package marginalia
  ;; Either bind `marginalia-cycle` globally or only in the minibuffer
  :bind (("M-A" . marginalia-cycle)
         :map minibuffer-local-map
         ("M-A" . marginalia-cycle))

  ;; The :init configuration is always executed (Not lazy!)
  :init

  ;; Must be in the :init section of use-package such that the mode gets
  ;; enabled right away. Note that this forces loading the package.
  (marginalia-mode))
#+end_src

* Adding custom annotators or classifiers

Minibuffer completion commands can specify the type of the candidates which are
being completed, called the *completion category*. For example the =M-x= command
(=execute-extended-command=) specifies the category =command=. However many
commands do not specify a completion category, this includes many of the Emacs
built-in completion commands.

In order to repair existing commands, Marginalia provides heuristic classifiers,
which try to determine the completion category based on the prompt string or
based on other properties of the completion candidates. You can for example
define that commands with a prompt containing "face", have the associated =face=
completion category.

#+begin_src emacs-lisp
  (add-to-list 'marginalia-prompt-categories '("face" . face))
#+end_src

Another useful classifier uses the =marginalia-command-categories= variable,
which allows do define the completion category per command name. This is
particularily useful if for example the prompt classifier yields a false
positive. The list of all available classifiers is specified by the variable
=marginalia-classifiers=. The completion categories are also important for
[[https://github.com/oantolin/embark][Embark]], which associates its minibuffer actions depending on the completion
commands.

Marginalia uses the annotators depending on the completion category of the
current command as registered in =marginalia-annotator-registry=. It is possible
to specify multiple annotators per completion category (for example with more or
less information). You can cycle between the different annotators by invoking
the =marginalia-cycle= command during the current completion.

An annotation function is a function taken a completion candidate string as
argument and returns the annotation string. For example a basic face annotator
can be written as follows:

#+begin_src emacs-lisp
  (defun my-face-annotator (cand)
    (when-let (sym (intern-soft cand))
      (concat (propertize " " 'display '(space :align-to center))
              (propertize "The quick brown fox jumps over the lazy dog" 'face sym))))
#+end_src

There are a few helper functions available internally which can be used to write
the annotation functions more conveniently, in particular =marginalia--fields=.
After defining the annotator, it must be added to the annotator registry.

#+begin_src emacs-lisp
  (add-to-list 'marginalia-annotator-registry
               '(face my-face-annotator marginalia-annotate-face builtin none))
#+end_src

We also add the annotator provided by Marginalia (=marginalia-annotate-face=),
the =builtin= annotator as defined by Emacs and the =none= annotator, which
disables the annotations. You can cycle between all of those annotators using
=marginalia-cycle= after invoking =M-x describe-face RET=.

* Disabling annotators, builtin or lightweight annotators

Marginalia activates rich annotators by default. Depending on your preference
you may want to use the builtin annotators or even no annotators by default and
only activate the annotators on demand by invoking ~marginalia-cycle~.

In order to use the builtin annotators by default, you can use the following
command. Replace =builtin= by =none= to disable annotators by default.

#+begin_src emacs-lisp
  (defun marginalia-use-builtin ()
    (interactive)
    (mapc
     (lambda (x)
       (setcdr x (cons 'builtin (remq 'builtin (cdr x)))))
     marginalia-annotator-registry))
#+end_src

If a completion category supports two annotators, you can toggle between
those using this command.

#+begin_src emacs-lisp
  (defun marginalia-toggle ()
    (interactive)
    (mapc
     (lambda (x)
       (setcdr x (append (reverse (remq 'none
                                        (remq 'builtin (cdr x))))
                         '(builtin none))))
     marginalia-annotator-registry))
#+end_src

After cycling the annotators you may want to automatically save the
configuration. This can be achieved using an advice which calls
~customize-save-variable~.

#+begin_src emacs-lisp
  (advice-add #'marginalia-cycle :after
              (lambda ()
                (let ((inhibit-message t))
                  (customize-save-variable 'marginalia-annotator-registry
                                           marginalia-annotator-registry))))
#+end_src

In order to disable an annotator permanently, the ~marginalia-annotator-registry~
can be modified. For example if you prefer to never see file annotations, you
can delete all file annotators from the registry.

#+begin_src emacs-lisp
  (setq marginalia-annotator-registry
        (assq-delete-all 'file marginalia-annotator-registry))
#+end_src

* Contributions

Since this package is part of [[http://elpa.gnu.org/packages/marginalia.html][GNU ELPA]] contributions require a copyright
assignment to the FSF.

Old versions

marginalia-0.7.tar.lz2021-Jun-20 130 KiB
marginalia-0.6.tar.lz2021-May-30 128 KiB