Kevin's Weblog

I didn’t take as many notes today. Really only two talks I went to were worth reporting on.

A talk about DTrace and how they used it to profile the performance of Twitter was quite good. They actually went through a full profiling session to show how you can progressively dig down through the diagnostics to pinpoint issues with a program. It was very inspiring. Some day I hope to be able to use an operating system at work that has DTrace. (I really need to spend some time with oprofile to see how it compares.) I was surprised how few people were at this talk; I wonder if that’s because most people are using Linux and thus it’s somewhat irrelevant to them.

Later in the day, I went to a talk from one of the authors of Jifty about implementing DSLs in Perl. Specifically, he’s talking about ‘internal DSLs’ which are implemented inside the host language. He showed 4 DSLs which they have created: Jifty::DBI::Schema, Template::Declare, Jifty::Dispatcher, and Test::WWW::Declare. These are languages for Rails-like schema migrations, HTML templating, HTTP dispatch rules, and mechanized web page testing, respectively. He talked very rapidly about what was involved to create the DSLs that they wanted and make it valid, working Perl, but honestly I could not absorb it as quickly as it went by. I’m planning to go look at the code more closely at some point to understand how they do it.

At the end of the day, I went to the Perl Lightning Talks, which were a mixed bag and which others took much better notes on. Then there was the Perl Foundation Auction, which took too long, followed by the State of the Onion, which is always hard to summarize, but my take was that Larry talked about all the different choices that go into designing a programming language, then assured us that Perl 6 makes all the right choices (including giving the programmer the ability to override many of the choices if they feel they need to).