emscripten/demos/cubescript.html

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<html>
<head>
<title>
Emscripten: CubeScript
</title>
<script src="cubescript.js"></script>
<script>
// print function which the cubescript engine will call
function print(text) {
document.getElementById('output').innerHTML += text + '<br>';
printed = true;
}
function execute(text) {
printed = false;
executeCS(text);
if (!printed) {
print('<small><i>(no output)</i></small>');
}
}
</script>
</head>
<body onload="document.getElementById('the_input').focus()">
<p>
This is an <a href="http://emscripten.org">Emscriptened</a> <a href="http://sauerbraten.org/docs/config.html#cubescript">CubeScript</a> engine.
The CubeScript engine from <a href="http://sauerbraten.org">Sauerbraten</a>, which is about 2,500 lines of C++, was compiled by
<a href="http://llvm.org/cmds/llvmgcc.html">llvm-gcc</a> into <a href="http://llvm.org/">LLVM</a> bitcode,
which was translated by Emscripten into JavaScript, which
you can run in your browser here. In other words, it's a script engine (for one language, and written in C++) running in another script engine
(the JavaScript engine in your browser, which is incidentally also written in C++, most likely).
</p>
</p>
Why? <i>[insert Internet meme joke here]</i> Seriously, though, this is a test of the capabilities of
<a href="http://emscripten.org">Emscripten</a>, since the CubeScript engine uses fairly complicated C++ (even stuff like
manually copying vtable pointers), and since compiling an actual, complete script engine seems like a useful milestone.
Also, it's a potential first step
towards bringing <a href="http://www.syntensity.com">Syntensity</a> (which is based on Sauerbraten) to the web.
</p>
<hr>
<p>
<b>Instructions</b>: For example, try entering the following commands in the input field below:
<ul>
<li><div style="font-family: Courier New,Courier,monospace;">echo Hello world</div></li>
<li><div style="font-family: Courier New,Courier,monospace;">x = 3 </div> <small><i>(note the spaces around the '=')</i></small></li>
<li><div style="font-family: Courier New,Courier,monospace;">echo $x</div></li>
<li><div style="font-family: Courier New,Courier,monospace;">echo Another number: (+ $x (* 5 10)) </div><small><i>(note the prefix notation, that is the same as <b>$x + (5*10)</b>)</i></small></li>
<li><div style="font-family: Courier New,Courier,monospace;">if (> $x 2) [ echo "x is bigger than 2" ] [ echo "x is not bigger than 2" ]</div></li>
</ul>
Check out the CubeScript <a href="http://sauerbraten.org/docs/config.html#cubescript">docs</a> or
<a href="http://cube.wikispaces.com/Cubescript+Tutorial">tutorial</a>
for more (but, they mainly talk about using CubeScript in Sauerbraten itself - much like most
JavaScript tutorials talk about using JavaScript in a web browser).
</p>
<hr>
<!-- Call the cubescript engine's execute() function -->
<form onsubmit="execute(the_input.value); the_input.value = ''; return false">
<b>Enter some CubeScript</b>:
<input type="text" id="the_input">
<input type="submit" value="execute">
</form>
<hr>
<div id="output" style="font-family: Courier New,Courier,monospace;"></div>
</body>
</html>