yasnippet/doc/index.org

Yet another snippet extension

• Quick start
• Organizing snippets
• Expanding Snippets
• Reference

Quick start

YASnippet is a template system for Emacs. It allows you to type an abbreviation and automatically expand it into function templates. Bundled language templates includes: C, C++, C#, Perl, Python, Ruby, SQL, LaTeX, HTML, CSS and more. The snippet syntax is inspired from TextMate's syntax, you can even import most TextMate snippets

YASnippet is an original creation of pluskid who also wrote its predecessor smart-snippet.

Watch a demo

On youtube.

Installation

Clone this repository somewhere

$ cd ~/.emacs.d/plugins
$ git clone https://github.com/capitaomorte/yasnippet

Add the following in your .emacs file:

(add-to-list 'load-path
              "~/.emacs.d/plugins/yasnippet")
(require 'yasnippet)
(yas-global-mode 1)

Add your own snippets to ~/.emacs.d/snippets by placing files there or invoking yas-new-snippet.

Import textmate snippets (rails example)

YASnippet lets you use TextMate bundles directly:

$ cd ~/.emacs.d/plugins
$ git clone https://github.com/capitaomorte/yasnippet
$ cd yasnippet
$ git submodule init
$ git submodule update
$ gem install plist trollop
$ rake convert_bundles             # will convert ruby, rails and html bundles from drnic

Then, in your .emacs file

(add-to-list 'load-path
              "~/.emacs.d/plugins/yasnippet")
(require 'yasnippet)
(setq yas-snippet-dirs '("~/.emacs.d/snippets" "~/.emacs.d/extras/imported"))
(yas-global-mode 1)

Open some rails file (model, app, etc) and start using the textmate snippets. Consider that this is a work-in-progress and many snippets/commands might not work. Patches welcome!

Contributing snippets

Please do not ask me to add snippets to the default collection under /snippets. This collection is considered frozen. By customizing yas-snippet-dirs you can point yasnippet to good snippet collections out there.

The extras/textmate-import.rb tool can import many actual Textmate snippets. I'm focusing on developing it and the accompanying yas-setup.el files that guide it with more difficult importations. The idea is to deprecate /snippets and replace it with extras/imported.

Documentation, issues, etc

Please refer to the comprehensive documentation for full customization and support. If you think you've found a bug, please report it on the GitHub issue tracker. (please do not submit new issues to the old googlecode tracker)

If you run into problems using YASnippet, or have snippets to contribute, post to the yasnippet forum. Thank you very much for using YASnippet!

Organizing snippets

Basic structure

Snippet collections can be stored in plain text files. They are arranged by sub-directories naming snippet tables. These mostly name Emacs major names.

.
|-- c-mode
|   `-- printf
|-- java-mode
|   `-- println
`-- text-mode
    |-- email
    `-- time

The collections are loaded into snippet tables which the triggering mechanism (see Expanding snippets) looks up and (hopefully) cause the right snippet to be expanded for you.

Setting up yas-snippet-dirs

The emacs variable yas-snippet-dirs tells YASnippet which collections to consider. It's used when you activate yas-global-mode or call yas-reload-all interactively.

The default considers:

• a personal collection that lives in ~/.emacs.d/snippets
• the bundled collection, taken as a relative path to yasnippet.el localtion

When you come across other snippet collections, do the following to try them out:

;; Develop in ~/emacs.d/mysnippets, but also
;; try out snippets in ~/Downloads/interesting-snippets
(setq yas-snippet-dirs '("~/emacs.d/mysnippets"
                           "~/Downloads/interesting-snippets"))

;; OR, keeping yasnippet's defaults try out ~/Downloads/interesting-snippets
(setq yas-snippet-dirs (append yas-snippet-dirs
                               '("~/Downloads/interesting-snippets")))

Collections appearing earlier in the list shadow snippets with same names appearing in collections later in the list. yas-new-snippet always stores snippets in the first collection.

The .yas-parents file

It's very useful to have certain modes share snippets between themselves. To do this, choose a mode subdirectory and place a .yas-parents containing a whitespace-separated list of other mode names. When you reload those modes become parents of the original mode.

.
|-- c-mode
|   |-- .yas-parents    # contains "cc-mode text-mode"
|   `-- printf
|-- cc-mode
|   |-- for
|   `-- while
|-- java-mode
|   |-- .yas-parents    # contains "cc-mode text-mode"
|   `-- println
`-- text-mode
    |-- email
    `-- time

TODO The .yas-make-groups file

If you place an empty plain text file .yas-make-groups inside one of the mode directories, the names of these sub-directories are considered groups of snippets and the menu is organized much more cleanly:

(TODO image)

Another alternative way to achieve this is to place a # group: directive inside the snippet definition. See Writing Snippets

$ tree ruby-mode/
ruby-mode/
|-- .yas-make-groups
|-- collections
|   |-- each
|   `-- ...
|-- control structure
|   |-- forin
|   `-- ...
|-- definitions
|   `-- ...
`-- general
   `-- ...

Yet another way to create a nice snippet menu is to write into .yas-make-groups a menu definition. TODO

TODO The .yas-setup.el file

TODO

TODO The .yas-compiled-snippet.el file

TODO

The .yas-skip file

Expanding Snippets

This section describes how YASnippet chooses snippets for expansion at point.

Maybe, you'll want some snippets to be expanded in a particular mode, or only under certain conditions, or be prompted using

Triggering expansion

To make a snippet expand after the cursor:

• Type the snippet's trigger key then calling yas-expand. It's bound to TAB and <tab> by default, to change it use

  (define-key yas-minor-mode-map (kbd "<tab>") nil)
  (define-key yas-minor-mode-map (kbd "TAB") nil)
  (define-key yas-minor-mode-map (kbd "<the new key>") 'yas-expand)

• Use the snippet's keybinding.
• Call yas-insert-snippet (use M-x yas-insert-snippet= or its keybinding C-c & C-s).
• By expanding directly from the "YASnippet" menu in the menu-bar
• Using hippie-expand
• Use m2m's excellent auto-complete

Reference