* sps-mode

This is an [[http://www.gnu.org/software/emacs/][Emacs]] minor mode and collection of commands for working with
[[http://common-lisp.net/project/parenscript/][Parenscript]] code in [[http://common-lisp.net/project/slime/][SLIME]] and sending it to the browser via [[https://github.com/skeeto/skewer-mode][Skewer]]. The goal is
to create an environment for hacking Parenscript which fits as naturally as
possible into the Lisp style of interactive development.

Note that this is very young code and there are certain to be serious problems.

There's at least one other project with related goals, [[https://github.com/3b/slime-proxy][slime-proxy]], though at
the time of writing it's unclear whether it's still being actively developed.

** Installation

=sps-mode= has both [[http://en.wikipedia.org/wiki/Common_Lisp][Common Lisp]] and Emacs dependencies.

- Common Lisp dependencies
  - Your preferred [[http://en.wikipedia.org/wiki/Common_Lisp][Common Lisp]] implementation
  - [[http://common-lisp.net/project/parenscript/][Parenscript]]

You almost certainly want to use [[http://www.quicklisp.org/beta/][Quicklisp]] to install Parenscript.

- Emacs dependencies
  - [[http://common-lisp.net/project/slime/][SLIME]]
  - [[https://github.com/skeeto/skewer-mode][Skewer]]
  - [[https://github.com/magnars/s.el][s.el]]
  - [[https://github.com/magnars/dash.el][dash.el]]

My recommendation is to install SLIME via the [[https://github.com/quicklisp/quicklisp-slime-helper][Quicklisp SLIME Helper]] and
the others through [[http://www.emacswiki.org/emacs/ELPA][ELPA]].

** Setup

To enable sps-mode in a SLIME buffer: =M-x sps-mode=.

To have =lisp-mode=, =slime-mode=, and =sps-mode= all enable automatically for
any file with an extension of ".paren":

#+BEGIN_SRC emacs-lisp
(add-to-list 'auto-mode-alist (cons "\\.paren\\'" 'lisp-mode))
(add-hook 'lisp-mode-hook
          #'(lambda ()
              (when (and buffer-file-name
                         (s-ends-with? ".paren" buffer-file-name))
                (unless (slime-connected-p)
                  (save-excursion (slime)))
                (sps-mode +1))))
#+END_SRC

=slime-mode= must be active for both expansion and evaluation commands. For
evaluation commands, =skewer-mode= is also required. (See below for a list of
the available commands).

Parenscript must be loaded in your Common Lisp image, and you'll probably also
want to import its symbols:

#+BEGIN_SRC common-lisp
(ql:quickload :parenscript)
(use-package :parenscript)
#+END_SRC

** Commands

*** Code expansion commands

These commands generate JavaScript from the Parenscript code and display it but
don't send it to the browser for evaluation:

    - =sps-expand-sexp=
    - =sps-expand-last-expression=
    - =sps-expand-defun=
    - =sps-expand-region=
    - =sps-expand-buffer=
    - =sps-expand-dwim=

From within an expansion buffer you can press "x" to send the JavaScript to the
browser.

*** Code evaluation commands

These commands first compile the Parenscript code to JavaScript and then
immediately send to it the browser to be evaluated:

    - =sps-eval-sexp=
    - =sps-eval-last-expression=
    - =sps-eval-defun=
    - =sps-eval-region=
    - =sps-eval-buffer=
    - =sps-eval-dwim=

** Keybindings

Many programming modes, including most Skewer modes, use keybindings which
overlap with SLIME's. To enable those bindings, thus shadowing SLIME's, you can
use =(sps-shadow-slime-keybindings!)=.

However /this isn't recommended/. There's a good chance you'll want the
flexibility to evaluate the code in an =sps-mode= buffer as either Common Lisp
or Parenscript, in which case you won't want to shadow the SLIME keybindings.
In this case you should assign key bindings yourself.

** Still do be done

    - Test against a wider array of code. Are there problems with quoting?
    - Better documentation.
    - Add a REPL and/or a scratch buffer.
    - See if more integration with SLIME is possible (e.g. the selector).
    - Command(s) for compiling with the output going to a file.
    - Similar support for [[http://weitz.de/cl-who/][CL-WHO]] and/or [[https://github.com/paddymul/css-lite][CSS-LITE]]?
    - Optional default keybindings that don't shadow SLIME.
    - Function(s) to add keybindings behind prefix keys (see js2r).
    - Get to know ELPA and packaging.
    - Add support for Customize.

** Contributing

Contributions are very welcome. Since I've just started working on this and
don't have everything figured out yet, please first contact me on GitHub or
send me an email so we can talk before you start working on something.