/expand-region.el

Emacs extension to increase selected region by semantic units.

Primary LanguageEmacs Lisp

expand-region.el Build Status Coverage Status

Expand region increases the selected region by semantic units. Just keep pressing the key until it selects what you want.

An example:

(setq alphabet-start "abc def")

With the cursor at the c, it starts by marking the entire word abc, then expand to the contents of the quotes abc def, then to the entire quote "abc def", then to the contents of the sexp setq alphabet-start "abc def" and finally to the entire sexp.

You can set it up like this:

(require 'expand-region)
(global-set-key (kbd "C-=") 'er/expand-region)

You can contract the region again with a negative prefix, if you expand too far.

Video

You can watch an intro to expand-region at Emacs Rocks.

Installation

I highly recommend installing expand-region through elpa.

It's available on marmalade and melpa:

M-x package-install expand-region

Language support

Expand region works fairly well with most languages, due to the general nature of the basic expansions:

er/mark-word
er/mark-symbol
er/mark-symbol-with-prefix
er/mark-next-accessor
er/mark-method-call
er/mark-inside-quotes
er/mark-outside-quotes
er/mark-inside-pairs
er/mark-outside-pairs
er/mark-comment
er/mark-url
er/mark-email
er/mark-defun

However, most languages also will benefit from some specially crafted expansions. For instance, expand-region comes with these extra expansions for html-mode:

er/mark-html-attribute
er/mark-inner-tag
er/mark-outer-tag

You can add your own expansions to the languages of your choice simply by creating a function that looks around point to see if it's inside or looking at the construct you want to mark, and if so - mark it.

There's plenty of examples to look at in these files.

After you make your function, add it to a buffer-local version of the er/try-expand-list.

Example:

Let's say you want expand-region to also mark paragraphs and pages in text-mode. Incidentally Emacs already comes with mark-paragraph and mark-page. To add it to the try-list, do this:

(defun er/add-text-mode-expansions ()
  (make-variable-buffer-local 'er/try-expand-list)
  (setq er/try-expand-list (append
                            er/try-expand-list
                            '(mark-paragraph
                              mark-page))))

(add-hook 'text-mode-hook 'er/add-text-mode-expansions)

Add that to its own file, and add it to the expand-region.el-file, where it says "Mode-specific expansions"

Warning: Badly written expansions might slow down expand-region dramatically. Remember to exit quickly before you start traversing the entire document looking for constructs to mark.

Contribute

If you make some nice expansions for your favorite mode, it would be great if you opened a pull-request. The repo is at:

https://github.com/magnars/expand-region.el

All changes must be accompanied by feature tests. They are written in Ecukes, a Cucumber for Emacs.

To fetch the test dependencies, install cask if you haven't already, then:

$ cd /path/to/expand-region
$ cask

Run the tests with:

$ ./run-tests.sh

If feature tests are missing for the mode you are changing, please make sure to add a set of basic tests around the functionality you're changing.

Contributors

  • Josh Johnston contributed er/contract-region
  • Le Wang contributed consistent handling of the mark ring, expanding into pairs/quotes just left of the cursor, and general code clean-up.
  • Raimon Grau added support for when transient-mark-mode is off.
  • Roland Walker added option to copy the contents of the most recent action to a register, and some fixes.
  • Damien Cassou added option to continue expanding/contracting with fast keys after initial expand.
  • Sylvain Rousseau fixed loads of little annoyances.
  • Ryan Mulligan cleaned up a lot of byte compilation warnings.
  • Lefteris Karapetsas added subword-mode expansions.

Language specific contributions

Thanks!

Changelog

From 0.9 to 0.10

  • Smarter expansion of ruby heredoc contents (Steve Purcell)
  • Add enh-ruby-mode expansions (Bradley Wright)
  • Add basic expansion er/mark-defun
  • Big cleanup of byte compilation warnings (Ryan Mulligan)
  • Better performance
  • Lots of bugfixes

From 0.8 to 0.9

  • Improve org-, clojure-, python-, latex-, cc- and ruby-modes
  • Add basic expansions: email and url
  • Add sml-mode expansions (Alexis Gallagher)
  • Add cperl-mode expansions (Kang-min Liu)
  • Add octave-mode expansions (Mark Hepburn)
  • Add web-mode expansions (Rotem Yaari)
  • Use Carton for dev-dependencies
  • Fix bad behavior in minibuffer (Sylvain Rousseau)
  • More robust comment expansions
  • Improve loading of expansions for all major modes

From 0.7 to 0.8

  • Improve js-, ruby-, python- and latex-modes
  • Support built-in javascript-mode
  • Handle narrowed buffers correctly
  • Include mode-specific expansions when autoloading
  • Provide option to copy the contents of the most recent action to a register
  • Add cc-mode specific expansions
  • Add customization to turn off skipping whitespace when expanding
  • Continue expanding/contracting with one key press (optional)

License

Copyright (C) 2011-2013 Magnar Sveen

Author: Magnar Sveen magnars@gmail.com Keywords: marking region

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.