iRi pending.en-usTue, 16 Sep 2014 18:18:06 -0000 While Star Trek was ahead of its time in many ways, you could tell they ... <p>While Star Trek was ahead of its time in many ways, you could tell they never lived with the technology they hypothesized. For instance, there's no episode in which Wesley Crusher walks around with his <a href=''>PADD</a> unlocked while cradling it on his chest, causing a Major Interstellar Diplomatic Incident when he accidentally ends up emailing pictures of his armpit to the Klingon High Council along with a text message consisting of "klxitijtjqtktkjjt", which is of course an ancient and dishonorable way of challenging the entire Council to a mandatory duel to the death.</p> <p>Fortunately, all I managed to do with my accidentally unlocked phone today was start the stopwatch and bring up the texting screen without actually sending anything. But still, it's sorta scary just what socially-horrible things you can do from that touchscreen.</p> (jerf)Tue, 16 Sep 2014 18:18:06 -0000 And the cat&#39;s in the cradle and the silver spoon, Little boy blue and the ... <p><i>And the cat's in the cradle and the silver spoon,<br /> Little boy blue and the man in the moon.<br /> "When you coming home, dad?" "I'm home right now,<br /> having some fun and how,<br /> You know we're having fun and how!"</i></p> (jerf)Sun, 27 Jul 2014 23:16:21 -0000 Go: More UNIX than UNIX <p>Go comes in part from Rob Pike and Ken Thompson, both influential in early UNIX. Both Rob Pike and Ken Thompson also were influential in working on <a href=''>Plan 9</a>, a followup to UNIX.</p> <p>UNIX's ideal is that "everything is a file". In Go terminology, this is a declaration that everything should be accessible via a uniform <tt>interface</tt>, which the OS specially privileges. One of Plan 9's core reasons for existing is that UNIX didn't take this anywhere near as far as it could be taken, and it goes much further in making everything accessible as a file in a directory structure.</p> <p>I'm skeptical of both of these approaches. Everything <i>isn't</i> a "file".</p> <p>There's numerous "files" that require <a href=''>ioctls</a> to correctly manipulate, which are arbitrary extensions outside of the file interface. On the flip side, there are all kinds of "files" that can't be seeked, such as sockets, or files that can't be closed, like UDP streams. Pretty much every element of the file interface is one that doesn't apply to some "file", somewhere.</p> <p>The <a href=''>Procrustean approach</a> to software engineering tends to have the same results as Procrustes himself did, gravely or even fatally wounding the code in question.</p> <p><a href="">Read the rest...</a></p> (jerf)Tue, 29 Apr 2014 14:20:39 -0000 Suture - Supervisor Trees for Go <p>Supervisor trees are one of the core ingredients in Erlang's reliability and <a href=''>let it crash philosophy</a>. A well-structured Erlang program is broken into multiple independent pieces that communicate via messages, and when a piece crashes, the supervisor of that piece automatically restarts it.</p> <p>This may not sound very impressive if you've never used it. But I have witnessed systems that I have written experience dozens of crashes per minute, but function correctly for 99% of the users. Even as I have been writing <a href=''>suture</a>, I have on occasion been astonished to flip my screen over to the console of Go program I've written with suture, and been surprised to discover that it's actually been merrily crashing away during my manual testing, but soldiering on so well I didn't even know.</p> <p>(This is, of course, immediately followed by improving my logging so I <i>do</i> know when it happens in the future. Being crash-resistant is good, but one should not "spend" this valuable resource frivolously!)</p> <p>I've been porting a system out of Erlang into Go for various other reasons, and I've missed having supervisor trees around. I decided to create them in Go. But this is one of those cases where we do not need a transliteration of the Erlang code into Go. For one thing, that's simply impossible as the two are mutually incompatible in some fundamental ways. We want an idiomatic <i>translation</i> of the functionality, which retains as much as possible of the original while perhaps introducing whatever new local capabilities into it make sense.</p> <p>To correctly do that, step one is to deeply examine not only the <i>what</i> of Erlang supervision trees, but the <i>why</i>, and then figure out how to translate.</p> <p><a href="">Read the rest...</a></p> (jerf)Tue, 22 Apr 2014 20:31:15 -0000 The Environment Object Pattern in Go <p>One of the things I've been really enjoying about Go is how easy testing is. The pervasive use of interfaces and composition-instead-of-inheritance synergize nicely for testing. But as I've expressed this online on reddit and Hacker News a couple of times, I've found that this does not seem to be a universally-shared opinion. Some have even commented on how hard it is to test in Go.</p> <p>Since we are all obviously using the same language, the difference must lie in coding behavior. I've internalized a lot of testing methodology over the years, and I find some of the things work even better in Go that most other imperative languages. Let me share one of my core tricks today, which I will call the Environment Object pattern, and why Go makes it incrementally easier to use than other similar (imperative) environments.</p> <p><a href="">Read the rest...</a></p> (jerf)Fri, 24 Jan 2014 01:31:40 -0000