/hy-mode

Hy mode for Emacs

Primary LanguageEmacs LispGNU General Public License v3.0GPL-3.0

hy-mode

Major mode for Emacs for editing buffer written in the Hy language. This mode is only compatible with Emacs 24 and above.

Installation

via MELPA

hy-mode is available in the MELPA repository. Do this, if MELPA isn't already in your sources:

(require 'package)
(add-to-list 'package-archives
             '("MELPA" . "http://melpa.milkbox.net/packages/" ))

Then run M-x package-refresh-contents to load the contents of the new repository, and M-x package-install RET hy-mode RET to install hy-mode.

Manual

To install, just copy hy-mode.el into a directory on your load path. Alernatively, you could always modify your load path to include a new directory. For instance:

$ mkdir ~/.emacs.d/hy-mode
$ cp hy-mode.el ~/.emacs.d/hy-mode/hy-mode.el

In your init file, (usually .emacs or .emacs.d/init.el), add this:

;; add the new dir to the load path
(add-to-list 'load-path "~/.emacs.d/hy-mode")
(require 'hy-mode)

Interacting with Hy from within Emacs

When in hy-mode, you can launch a Hy REPL by launching a Lisp inferior process:

M-x inferior-lisp

You can customize the path (also special options to the REPL like --spy) to the Hy REPL by setting the variable hy-mode-inferior-lisp-command to point to Hy executable's path. This can be done via M-x customize-group RET hy-mode and setting hy-mode inferior Lisp command.

From your hy-mode buffer you can use the following default keybindings:

  • C-M-x: send the whole function (top-level form) for evaluation in the REPL
  • C-x C-e: send the expression at current point for evaluation
  • C-c C-z: switch to the lisp buffer
  • C-c C-l: load the file in REPL

Other recommended settings

Since hy-mode is a lisp like mode, it can use the goodness from some minor modes used for lisp such as smartparens or paredit minor modes which support excellent movement and navigation ability other than keeping the s-expressions balanced.

; eg: Adding paredit minor mode
(add-hook 'hy-mode-hook 'paredit-mode)

; alternatively you could enable this to a bunch of lisp modes
(dolist (lisp-mode '(scheme emacs-lisp lisp clojure hy))
  (add-hook (intern (concat (symbol-name lisp-mode) "-mode-hook"))
		'paredit-mode))

Special note for Windows users:

Depending on your PYTHONPATH and Emacs path settings, invoking inferior Lisp may not work by default. You may need to customize the path to Hy REPL to something like:

(setq hy-mode-inferior-lisp-command "/path/to/python -i /path/to/hy-script.py")

About Hy

More information about Hy can be found at http://hylang.org.