Category Archives: Technology

I’ve Switched to Darcs

Software

I’ve converted 24 public projects from Subversion or Arch to Darcs, preserving full history, as I mentioned earlier. It all went very smoothly. I’m even maintaining my Arch utilities in darcs :-)

Some small observations:

  • Committing early and often is good.
  • When a commit is virtually instantaneous, it’s easy to commit early and often. A commit in darcs doesn’t require it to hit the network.
  • Branching is a frequent need and is done far to infrequently. But Darcs makes it even easier than Arch. Very nice.

I’m Switching to Darcs

Software

I’ve been using Arch/tla/baz for quite awhile now; I switched from Subversion awhile back. But they’ve got a bunch of things that annoy me. Offline working is clumsy. Performace is bad, and to make it even approach decent, you have to dedicate a huge amount of space to a revision library cache. Commands, even with baz, are clumsy and require an inordinate amount of typing. It’s still better than CVS and SVN, with its merging and all, but still — it’s been annoying.

Enter darcs. I’ve been keeping an eye on it for awhile, and it looks like it’s become quite stable, useful, and fast recently. I tried it out awhile back, and it wasn’t really “there” yet. I tried it out again this week, and must say that darcs is great. I’m converting all my Arch and Subversion stuff to Darcs.

The thing that really impressed me is this Darcs mirror of the Linux kernel Bitkeeper repository. Darcs is fast over this, far nicer than Arch was (I did a similar project in Arch awhile back), and it uses less than 1GB of disk space for a complete mirror.

Oh, and I wrote a 100-line Haskell program to convert Arch stuff to Darcs: arch2darcs. You can see an example of a converted repository at here. There’s also a program called Tailor (I didn’t write this one) that does a bidirectional sync between Darcs and CVS or Subversion. Sweet.

I’m happily converting the rest of my Arch and SVN stuff to Darcs today. Woohoo.

Randomly-Generated CS Paper Accepted at Conference

Humor, Software

Now this is absolutely hilarious. A randomly-generated computer science paper has been accepted to a conference. Not just that, but the grad students behind the program that generated it are raising money so they can attend and deliver a randomly-generated talk.

Read the paper and you’ll probably burst out laughing.

If you don’t know much about computer science, it may look shockingly real.

Today’s Reading + Perl Community

General, Programming

Cliff’s memories of Easter are a great read.

A study showing that a significant number of people exhibit violence towards their computer when it malfunctions, and another significant number of people attempt to sweet-talk it.

Shapr posted a link to the extremeperl mailing list. I found this post on the value of learning languages to be insightful.

Along a similar line, there’s an intriguing post on The Sequence from a Perl hacker looking at the Haskell community. I think he’s right.

These Perl people are really impressing me lately. My respect for the Perl commnuity has really shot upwards lately. And I am similarly disappointed in many of the directions Python is taking these days. Nice time to be using Haskell :-)

Haskell: The Humbling Language

Programming

Usually when I learn a new programming language, I’ll hang out on its mailing lists and IRC channels, learning from the answers given to other people’s questions, and asking my own. After a month or two, I usually feel fairly good with my abilities; that I could answer most of the questions, and understand most of the questions.

Well, I’ve been using Haskell for about 6 months now. I really like Haskell, and it’s a great language to use, and it’s already my preferred language.

But here’s what’s unique about Haskell. The more I use it, and the more I participate with the Haskell community, the more I realize just how much there is that I could learn. And it seems that I’m not alone with that feeling.

I wonder why Haskell is unique this way.

More on Asterisk

Technology, Uncategorized

Since I wrote about Asterisk, the Free Software PBX, a few days ago, I’ve decided to start tinkering with it. In a word, Asterisk is awesome. It has lots of features, and is free, too.

Asterisk lets you manage your phones. You can set up extensions, letting phones call each other. You can also set up routes out — connections to other offices, to the public telephone network (PSTN), or to other VOIP users. You can hook to the PSTN with either a $10 hardware device, or by using one of the many cheap VOIP providers, or whatever. And you can set up automatic call routing rules — for instance, you might route local calls over your local PSTN link, but fall back to a VOIP provider if your local link is in use.

Here are some links for Asterisk information:

  • The Asterisk wiki, an excellent resource
  • VOIP phones, hardware phones that take an Ethernet cable, or software phonse that run on a PC
  • VOIP service providers, listing some free IP-to-IP VOIP providers, as well as VOIP-to-PSTN and PSTN-to-VOIP companies.
    • FreeWorld Dialup is an excellent free VOIP-to-VOIP provider. They also have peering with many other VOIP networks; you can, for instance, call Vonage customers for free via FWD. FWD also has a free link to the PSTN for calling toll-free numbers in several countries.
    • VoipJet lets you call anywhere in the USA for 1.3 cents per minute, and LiveVOIP does the same for 1.2 cents per minute. With LiveVOIP, you can also purchase a phone number for incoming calls for $4 to $8 per month.
    • IPkall gives you a free local number in Washington state that forwards calls to your FWD account. There are some other companies that do similar things, too. Many also have very low rates on incoming toll-free calls.
  • Asterisk tips and tricks is a great page
  • Asterisk Handbook Project
  • Asterisk Documentation Project