mirror of
https://github.com/samsonjs/elisp.js.git
synced 2026-03-25 09:15:49 +00:00
129 lines
3.6 KiB
Text
129 lines
3.6 KiB
Text
Emacs Lisp implementation in JavaScript.
|
|
|
|
Copyright (c) 2009 Sami Samhuri - sami.samhuri@gmail.com
|
|
|
|
Released under the terms of the MIT license. See the included file
|
|
LICENSE.
|
|
|
|
Latest version available on github:
|
|
|
|
http://github.com/samsonjs/elisp.js
|
|
|
|
|
|
Introduction
|
|
(or "You must be kidding")
|
|
==========================
|
|
|
|
I'm not 100% sure why I think this might be useful to somebody. The
|
|
idea of editing code directly on github or bitbucket in a web browser
|
|
is pretty cool though, and if you're going to do such a thing why not
|
|
use the best tools available. IMO those tools are written in Emacs
|
|
Lisp so I would like to use them in the browser. Maybe with some
|
|
HTML5 offline goodness thrown in.
|
|
|
|
Seeing Ymacs[1] in action[2] was also an inspiration to start this
|
|
project as I've had it on my TODO list for several months now. Emacs
|
|
in the browser could be a reality; Ymacs is proof.
|
|
|
|
[1] http://www.ymacs.org/
|
|
[2] http://www.ymacs.org/demo/
|
|
|
|
|
|
Getting Started
|
|
===============
|
|
|
|
Command line
|
|
------------
|
|
|
|
If you have rlwrap and js then just run el.sh. If not install a
|
|
JavaScript shell of your choice, and I recommend you install rlwrap
|
|
(readline wrap). Edit el.sh to reflect whether or not you use rlwrap
|
|
and your shell's name or path. Then run el.sh. I've only run this
|
|
under SpiderMonkey so I have no idea if it works under any other
|
|
implementations. Glad to accept info and/or patches.
|
|
|
|
Type a 'Q' or 'q' to quit the repl. Or anything that starts with Q,
|
|
like 'quickly quit lisp!'. (If lisp freaks out because you entered ^D
|
|
or something ^C or ^Z should still get you out.)
|
|
|
|
|
|
Emacs
|
|
-----
|
|
|
|
I use Emacs and js-comint.el[3] with inferior-js set to
|
|
/opt/local/bin/js, which is SpiderMonkey[4] from MacPorts[5] on Snow
|
|
Leopard.
|
|
|
|
[3] http://js-comint-el.sourceforge.net/
|
|
[4] http://www.mozilla.org/js/spidermonkey/
|
|
[5] http://www.macports.org/
|
|
|
|
For loading code C-c b sends the buffer to the JS repl. I also use
|
|
the EL.rep (read-eval-print), EL.parse, EL.eval, and EL.print
|
|
functions defined in el/repl.js
|
|
|
|
Here's an example:
|
|
|
|
% cd Projects/elisp.js
|
|
% rlwrap js
|
|
js> load('el.js')
|
|
elisp>
|
|
(defvar *directory* "/Users/sjs" "My home directory")
|
|
elisp>
|
|
*directory*
|
|
["string", "/Users/sjs"]
|
|
elisp>
|
|
(setq foo 1 bar 2 baz 3)
|
|
["number", 3]
|
|
elisp>
|
|
(/ (+ foo bar baz) 3)
|
|
["number", 2]
|
|
elisp>
|
|
(string-match "[a-z]lurgh" (symbol-name 'foo-blurgh))
|
|
["number", 4]
|
|
elisp>
|
|
q
|
|
js>
|
|
|
|
(If you know how to print without a trailing newline in SpiderMonkey
|
|
please let me know.)
|
|
|
|
There are other interfaces into the parser and evaluator besides the
|
|
shortcuts. new EL.Parser([input]) returns a parser object and likewise
|
|
new EL.Evaluator([exprs]) returns an evaluator object.
|
|
|
|
Mainly toy functions that do extremely simple operations on numbers
|
|
and strings can be implemented right now. Stay tuned, or better yet
|
|
hack away and submit a pull request on github[6].
|
|
|
|
[6] http://github.com/samsonjs/elisp.js
|
|
|
|
|
|
What's here?
|
|
============
|
|
|
|
Not much compared to the real thing but it's a decent start for < 1000
|
|
lines.
|
|
|
|
* parser/reader. there's no lexing to tokens we go straight to tagged
|
|
data. (ints, floats, strings, symbols, lists, quoted expressions)
|
|
|
|
* symbol table, but needs to be replaced ASAP.
|
|
(functions & variables separate)
|
|
|
|
* (broken) lexical scoping
|
|
|
|
* expression evaluator
|
|
|
|
* simple tagged primitive types
|
|
(string, symbol, lambda, number, cons)
|
|
|
|
* special forms for defvar, defun, set, setq, if, and quote
|
|
|
|
* eval/apply for atoms, function calls, and a few special forms
|
|
|
|
* a few primitive math ops
|
|
(thanks to JS' overloading + works on strings too)
|
|
|
|
* 2 horrible print functions
|
|
(JS "pretty" printer & a half-assed Lisp print)
|