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diff --git a/.html/dev/entry-points.html b/.html/dev/entry-points.html new file mode 100644 index 0000000..717c320 --- /dev/null +++ b/.html/dev/entry-points.html @@ -0,0 +1,134 @@ +<!DOCTYPE html> +<html> +<head> + <title> + The Codex » + Entry Points + </title> + + <link + rel='stylesheet' + type='text/css' + href='http://fonts.googleapis.com/css?family=Buenard:400,700&subset=latin,latin-ext'> + <link + rel="stylesheet" + type="text/css" + href="../media/css/reset.css"> + <link + rel="stylesheet" + type="text/css" + href="../media/css/grimoire.css"> +</head> +<body> + +<div id="shell"> + + <ol id="breadcrumbs"> + + <li class="crumb-0 not-last"> + + <a href="../">index</a> + + </li> + + <li class="crumb-1 not-last"> + + <a href="./">dev</a> + + </li> + + <li class="crumb-2 last"> + + entry-points + + </li> + + </ol> + + + + <div id="article"> + <h1 id="entry-points">Entry Points</h1> +<p>The following captures a conversation from IRC:</p> +<blockquote> +<p><a href="https://twitter.com/derspiny">Owen J</a>: Have you run across the idea +of an "entry point" in a runtime yet? (You've definitely used it, just +possibly not known it had a name.)</p> +<p><a href="https://twitter.com/aeleitch">Alex L</a>: I have not!</p> +<p><a href="https://twitter.com/derspiny">Owen J</a>: It's the point where the +execution of the outside system -- the OS, the browser, the Node +runtime, whatever -- stops and the execution of your code starts. Some +platforms only give you one: C on Unix is classic, where there's only +two entry points: main and signal handlers (and a lot of apps only use +main). JS gives you <em>a shit fucking ton</em> of entry points.</p> +<p><a href="https://twitter.com/derspiny">Owen J</a>: In a browser, the pageload +process is an entry point: your code gets run when the browser +encounters a <code><script></code> tag. So is every event handler. There's none +of your code running when an event handler starts, only the browser +is running. So is every callback from an external service, like +<code>XmlHttpRequest</code> or <code>EventSource</code> or the <code>File</code> APIs. In Node, the top +level of your main script is an entry point, but so is every callback +from an external service.</p> +<p><a href="https://twitter.com/aeleitch">Alex L</a>: Ahahahahahahaha oh my +god. There is no way for me to contain them all. <em>everything the light +touches.</em></p> +<p><a href="https://twitter.com/derspiny">Owen J</a>: This is important for +reasoning about exception handling! <em>In JS</em>, exception handling only +propagates one direction: towards the entry point of this sequence of +function calls.</p> +<p><a href="https://twitter.com/aeleitch">Alex L</a>: Yes. This is what <em>I</em> call a +stack trace.</p> +<p><a href="https://twitter.com/derspiny">Owen J</a>: If an exception escapes from +an entry point, the JS runtime logs it, and then the outside runtime +takes over again. That's one of the ways callbacks from external +services fuck up the idea of a stack trace as a map of control flow.</p> +<p><a href="https://twitter.com/aeleitch">Alex L</a>: Huh. Yes. Yes I can see +that. I mean, in my world, control flow is a somewhat handwavey idea +right now. I'm starting to understand why so many people hate JS-land.</p> +<p><a href="https://twitter.com/derspiny">Owen J</a>: Sure. But, for example, a +promise chain is a tool for restructuring control flow. In principle, +error handling should provide <em>some</em> kind of map of that, to allow +programmers -- you -- to diagnose how a program reached a given error +state and maybe one day fix the problem. In THIS future, none of them +do that well, though.</p> +<p><a href="https://twitter.com/aeleitch">Alex L</a>: Yes. Truly the darkest +timeline, but this reviews why I am having these concerns.</p> +</blockquote> + </div> + + + +<div id="comments"> +<div id="disqus_thread"></div> +<script type="text/javascript"> + /* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */ + var disqus_shortname = 'grimoire'; // required: replace example with your forum shortname + + /* * * DON'T EDIT BELOW THIS LINE * * */ + (function() { + var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true; + dsq.src = 'http://' + disqus_shortname + '.disqus.com/embed.js'; + (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq); + })(); +</script> +<noscript>Please enable JavaScript to view the <a href="http://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript> +<a href="http://disqus.com" class="dsq-brlink">comments powered by <span class="logo-disqus">Disqus</span></a> +</div> + + + + <div id="footer"> + <p> + + The Codex — + + Powered by <a href="http://markdoc.org/">Markdoc</a>. + +<a href="https://bitbucket.org/ojacobson/grimoire.ca/src/master/wiki/dev/entry-points.md">See this page on Bitbucket</a> (<a href="https://bitbucket.org/ojacobson/grimoire.ca/history-node/master/wiki/dev/entry-points.md">history</a>). + + </p> + </div> + +</div> +</body> +</html>
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