https://github.com/jwiegley/use-package.git
git clone 'git://github.com/jwiegley/use-package.git'
The meaning of :init
has been changed: It now always happens before
package load, whether :config
has been deferred or not. This means that
some uses of :init
in your configuration may need to be changed to :config
(in the non-deferred case). For the deferred case, the behavior is unchanged
from before.
Also, because :init
and :config
now mean “before” and “after”, the :pre-
and :post-
keywords are gone, as they should no longer be necessary.
Lastly, an effort has been made to make your Emacs start even in the presence
of use-package configuration failures. So after this change, be sure to check
your *Messages*
buffer. Most likely, you will have several instances where
you are using :init
, but should be using :config
(this was the case for me
in a number of places).
I am removing this feature for now because it can result in a nasty inconsistency. Consider the following definition:
(use-package vkill
:commands vkill
:idle (some-important-configuration-here)
:bind ("C-x L" . vkill-and-helm-occur)
:init
(defun vkill-and-helm-occur ()
(interactive)
(vkill)
(call-interactively #'helm-occur))
:config
(setq vkill-show-all-processes t))
If I load my Emacs and wait until the idle timer fires, then this is the sequence of events:
:init :idle <load> :config
But if I load Emacs and immediately type C-x L without waiting for the idle timer to fire, this is the sequence of events:
:init <load> :config :idle
It's possible that the user could use featurep
in their idle to test for
this case, but that's a subtlety I'd rather avoid.
:defer [N]
causes the package to be loaded – if it has not already been –
after N
seconds of idle time.
(use-package back-button
:commands (back-button-mode)
:defer 2
:init
(setq back-button-show-toolbar-buttons nil)
:config
(back-button-mode 1))
:preface
can be used to establish function and variable definitions that
will 1) make the byte-compiler happy (it won't complain about functions whose
definitions are unknown because you have them within a guard block), and 2)
allow you to define code that can be used in an :if
test.
Note that whatever is specified within :preface
is evaluated both at load
time and at byte-compilation time, in order to ensure that definitions are
seen by both the Lisp evaluator and the byte-compiler, so you should avoid
having any side-effects in your preface, and restrict it merely to symbol
declarations and definitions.
What :defines
does for variables, :functions
does for functions.
This means you should put the following at the top of your Emacs, to further reduce load time:
(eval-when-compile
(require 'use-package))
(require 'diminish) ;; if you use :diminish
(require 'bind-key) ;; if you use any :bind variant
use-package
The use-package
macro allows you to isolate package configuration in your
.emacs
file in a way that is both performance-oriented and, well, tidy. I
created it because I have over 80 packages that I use in Emacs, and things
were getting difficult to manage. Yet with this utility my total load time is
around 2 seconds, with no loss of functionality!
Here is the simplest use-package
declaration:
(use-package foo)
This loads in the package foo
, but only if foo
is available on your
system. If not, a warning is logged to the *Messages*
buffer. If it
succeeds, a message about "Loading foo"
is logged, along with the time it
took to load, if it took over 0.1s.
Use the :init
keyword to execute code before a package is loaded. It
accepts one or more form, up until the next keyword:
(use-package foo
:init
(setq foo-variable t))
Similarly, :config
can be used to execute code after a package is loaded.
In cases where loading is done lazily (see more about autoloading below), this
execution is deferred until after the autoload occurs:
(use-package foo
:init
(setq foo-variable t)
:config
(foo-mode 1))
As you might expect, you can use :init
and :config
together:
(use-package color-moccur
:commands (isearch-moccur isearch-all)
:bind ("M-s O" . moccur)
:init
(bind-key "M-o" 'isearch-moccur isearch-mode-map)
(bind-key "M-O" 'isearch-moccur-all isearch-mode-map)
:config
(use-package moccur-edit))
In this case, I want to autoload the commands isearch-moccur
and
isearch-all
from color-moccur.el
, and bind keys both at the global level
and within the isearch-mode-map
(see next section). When the package is
actually loaded (by using one of these commands), moccur-edit
is also be
loaded, to allow editing of the moccur
buffer.
Another common thing to do when loading a module is to bind a key to primary commands within that module:
(use-package ace-jump-mode
:bind ("C-." . ace-jump-mode))
This does two things: first, it creates an autoload for the ace-jump-mode
command and defers loading of ace-jump-mode
until you actually use it.
Second, it binds the key C-.
to that command. After loading, you can use
M-x describe-personal-keybindings
to see all such keybindings you've set
throughout your .emacs
file.
A more literal way to do the exact same thing is:
(use-package ace-jump-mode
:commands ace-jump-mode
:init
(bind-key "C-." 'ace-jump-mode))
When you use the :commands
keyword, it creates autoloads for those commands
and defers loading of the module until they are used. Since the :init
form
is always run – even if ace-jump-mode
might not be on your system –
remember to restrict :init
code to only what would succeed either way.
The :bind
keyword takes either a cons or a list of conses:
(use-package hi-lock
:bind (("M-o l" . highlight-lines-matching-regexp)
("M-o r" . highlight-regexp)
("M-o w" . highlight-phrase)))
The :commands
keyword likewise takes either a symbol or a list of symbols.
Similar to :bind
, you can use :mode
and :interpreter
to establish a
deferred binding within the auto-mode-alist
and interpreter-mode-alist
variables. The specifier to either keyword can be a cons cell, a list, or
just a string:
(use-package ruby-mode
:mode "\\.rb\\'"
:interpreter "ruby")
;; The package is "python" but the mode is "python-mode":
(use-package python
:mode ("\\.py\\'" . python-mode)
:interpreter ("python" . python-mode))
If you aren't using :commands
, :bind
, :bind*
, :bind-keymap
,
:bind-keymap*
, :mode
, or :interpreter
(all of which imply :defer
; see
the docstring for use-package
for a brief description of each), you can
still defer loading with the :defer
keyword:
(use-package ace-jump-mode
:defer t
:init
(autoload 'ace-jump-mode "ace-jump-mode" nil t)
(bind-key "C-." 'ace-jump-mode))
This does exactly the same thing as the other two commands above.
In almost all cases you don't need to manually specify :defer t
. This is
implied whenever :bind
or :mode
or :interpreter
is used. Typically, you
only need to specify :defer
if you know for a fact that some other package
will do something to cause your package to load at the appropriate time, and
thus you would like to defer loading even though use-package isn't creating
any autoloads for you.
You can override package deferral with the :demand
keyword. Thus, even if
you use :bind
, using :demand
will force loading to occur immediately and
not establish an autoload for the bound key.
When a package is loaded, and if you have use-package-verbose
set t or if
the package takes longer than 0.1s to load, you will see a message to indicate
this loading activity in the *Messages*
buffer. The same will happen for
configuration, or :config
blocks that take longer than 0.1s to execute. In
general, you should keep :init
forms as simple and quick as possible, and
put as much as you can get away with into the :config
block. This way,
deferred loading can help your Emacs to start as quickly as possible.
Additionally, if an error occurs while initializing or configuring a package,
this will not stop your Emacs from loading. Rather, the error will be
captured by use-package
, and reported to a special *Warnings*
popup
buffer, so that you can debug the situation in an otherwise functional Emacs.
You can use the :if
keyword to predicate the loading and initialization of
modules. For example, I only want edit-server
running for my main,
graphical Emacs, not for other Emacsen I may start at the command line:
(use-package edit-server
:if window-system
:init
(add-hook 'after-init-hook 'server-start t)
(add-hook 'after-init-hook 'edit-server-start t))
The :disabled
keyword can turn off a module you're having difficulties with,
or to stop loading something you're not using at the present time:
(use-package ess-site
:disabled t
:commands R)
When byte-compiling your .emacs
file, disabled declarations are ommitted
from the output entirely, to accelerate startup times.
Another feature of use-package
is that it always loads every file that it
can when .emacs
is being byte-compiled. This helps to silence spurious
warnings about unknown variables and functions.
However, there are times when this is just not enough. For those times, use
the :defines
and :functions
keywords to introduce dummy variable and
function declarations solely for the sake of the byte-compiler:
(use-package texinfo
:defines texinfo-section-list
:commands texinfo-mode
:init
(add-to-list 'auto-mode-alist '("\\.texi$" . texinfo-mode)))
If you need to silence a missing function warning, you can use :functions
:
(use-package ruby-mode
:mode "\\.rb\\'"
:interpreter "ruby"
:functions inf-ruby-keys
:config
(defun my-ruby-mode-hook ()
(require 'inf-ruby)
(inf-ruby-keys))
(add-hook 'ruby-mode-hook 'my-ruby-mode-hook))
Normally, use-package
will load each package at compile time before
compiling the configuration, to ensure that any necessary symbols are in scope
to satisfy the byte-compiler. At times this can cause problems, since a
package may have special loading requirements, and all that you want to use
use-package
for is to add a configuration to the eval-after-load
hook. In
such cases, use the :no-require
keyword, which implies :defer
:
(use-package foo
:no-require t
:config
(message "This is evaluated when `foo' is loaded"))
If your package needs a directory added to the load-path
in order to load,
use :load-path
. This takes a symbol, a function, a string or a list of
strings. If the path is relative, it is expanded within
user-emacs-directory
:
(use-package ess-site
:load-path "site-lisp/ess/lisp/"
:commands R)
Note that when using a symbol or a function to provide a dynamically generated
list of paths, you must inform the byte-compiler of this definition so the
value is available at byte-compilation time. This is done by using the
special form eval-and-compile
(as opposed to eval-when-compile
). Further,
this value is fixed at whatever was determined during compilation, to avoid
looking up the same information again on each startup:
(eval-and-compile
(defun ess-site-load-path ()
(shell-command "find ~ -path ess/lisp")))
(use-package ess-site
:load-path (lambda () (list (ess-site-load-path)))
:commands R)
use-package
also provides built-in support for the diminish utility – if
you have that installed. Its purpose is to remove strings from your mode-line
that provide no useful information. It is invoked with the :diminish
keyword, which is passed either a minor mode symbol, a cons of the symbol and
its replacement string, or just a replacement string, in which case the minor
mode symbol is guessed to be the package name with “-mode” appended at the
end:
(use-package abbrev
:diminish abbrev-mode
:config
(if (file-exists-p abbrev-file-name)
(quietly-read-abbrev-file)))
package.el
usersYou can use use-package
to load packages from ELPA with package.el
. This
is particularly useful if you share your .emacs
among several machines; the
relevant packages are download automatically once declared in your .emacs
.
The :ensure
keyword causes the package(s) to be installed automatically if
not already present on your system:
(use-package magit
:ensure t)
If you need to install a different package from the one named by
use-package
, you can specify it like this:
(use-package tex-site
:ensure auctex)
Lastly, when running on Emacs 24.4 or later, use-package can pin a package to
a specific archive, allowing you to mix and match packages from different
archives. The primary use-case for this is preferring packages from the
melpa-stable
and gnu
archives, but using specific packages from melpa
when you need to track newer versions than what is available in the stable
archives.
By default package.el
prefers melpa
over melpa-stable
due to the
versioning (> evil-20141208.623 evil-1.0.9)
, so even if you are tracking
only a single package from melpa
, you will need to tag all the non-melpa
packages with the appropriate archive.
If you want to manually keep a package updated and ignore upstream updates,
you can pin it to manual
, which as long as there is no repository by that
name, will Just Work(tm).
use-package
throws an error if you try to pin a package to an archive that
has not been configured using package-archives
(apart from the magic
manual
archive mentioned above):
Archive 'foo' requested for package 'bar' is not available.
Example:
(use-package company
:ensure t
:pin melpa-stable)
(use-package evil
:ensure t)
;; no :pin needed, as package.el will choose the version in melpa
(use-package adaptive-wrap
:ensure t
;; as this package is available only in the gnu archive, this is
;; technically not needed, but it helps to highlight where it
;; comes from
:pin gnu)
(use-package org
:ensure t
;; ignore org-mode from upstream and use a manually installed version
:pin manual)
NOTE: the :pin
argument has no effect on emacs versions < 24.4.
NOTE: if you pin a lot of packages, it will be slightly slower to start
Emacs compared to manually adding all packages to the
package-pinned-packages
variable. However, should you do it this way, you
need to keep track of when (package-initialize)
is called, so letting
use-package
handle it for you is arguably worth the cost.
Starting with version 2.0, use-package
is based on an extensible framework
that makes it easy for package authors to add new keywords, or modify the
behavior of existing keywords.
The first step is to add your keyword at the right place in
use-package-keywords
. This list determines the order in which things will
happen in the expanded code. You should never change this order, but it gives
you a framework within which to decide when your keyword should fire.
Define a normalizer for your keyword by defining a function named after the keyword, for example:
(defun use-package-normalize/:pin (name-symbol keyword args)
(use-package-only-one (symbol-name keyword) args
(lambda (label arg)
(cond
((stringp arg) arg)
((symbolp arg) (symbol-name arg))
(t
(use-package-error
":pin wants an archive name (a string)"))))))
The job of the normalizer is take a list of arguments (possibly nil), and turn
it into the single argument (which could still be a list) that should appear
in the final property list used by use-package
.
Once you have a normalizer, you must create a handler for the keyword:
(defun use-package-handler/:pin (name-symbol keyword archive-name rest state)
(let ((body (use-package-process-keywords name-symbol rest state)))
;; This happens at macro expansion time, not when the expanded code is
;; compiled or evaluated.
(if (null archive-name)
body
(use-package-pin-package name-symbol archive-name)
(use-package-concat
body
`((push '(,name-symbol . ,archive-name)
package-pinned-packages))))))
Handlers can effect on the handling of keywords in two ways. First, it can
modify the state
plist before recursively processing the remaining keywords,
to influence keywords that pay attention to the state (one example is the
state keyword :deferred
, not to be confused with the use-package
keyword
:defer
). Then, once the remaining keywords have been handled and their
resulting forms returned, the handler may manipulate, extend, or just ignore
those forms.
The task of each handler is to return a list of forms representing code to
be inserted. It does not need to be a progn
list, as this is handled
automatically in other places. Thus it is very common to see the idiom of
using use-package-concat
to add new functionality before or after a code
body, so that only the minimum code necessary is emitted as the result of a
use-package
expansion.
After the keyword has been inserted into use-package-keywords
, and a
normalizer and a handler defined, you can now test it by seeing how usages of
the keyword will expand. For this, temporarily set use-package-debug
to
t
, and just evaluate the use-package
declaration. The expansion will be
shown in a special buffer called *use-package*
.
On my Retina iMac, the “Mac port” variant of Emacs 24.4 loads in 0.57s, with around 218 packages configured (nearly all of them lazy-loaded). However, I experience no loss of functionality, just a bit of latency when I'm first starting to use Emacs (due to the autoloading). Since I also use idle-loading for many packages, perceived latency is typically reduced overall.
On Linux, the same configuration loads in 0.32s.
If I don't use Emacs graphically, I can test the absolute minimum times. This is done by running:
time emacs -l init.elc -batch --eval '(message "Hello, world!")'
On the Mac I see an average of 0.36s for the same configuration, and on Linux 0.26s.