Comments on: Lessons learned in class http://www.drmaciver.com/2008/06/lessons-learned-in-class/ Mon, 06 Feb 2012 22:56:11 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: david http://www.drmaciver.com/2008/06/lessons-learned-in-class/#comment-356 david Tue, 17 Jun 2008 21:56:55 +0000 http://www.drmaciver.com/?p=169#comment-356 Indeed. The actual code format is a bit crufty, but the overall structure is very straightforward. And yes, the spec is full of instances of variant types. The constant pool is indeed a perfect example. :-) Indeed. The actual code format is a bit crufty, but the overall structure is very straightforward.

And yes, the spec is full of instances of variant types. The constant pool is indeed a perfect example. :-)

]]> By: DavidLG http://www.drmaciver.com/2008/06/lessons-learned-in-class/#comment-355 DavidLG Tue, 17 Jun 2008 21:55:21 +0000 http://www.drmaciver.com/?p=169#comment-355 Fair enough. It's a very nicely-documented format. On a side note, the constant pool is a perfect example of something made much easier by Scala case classes. Fair enough. It’s a very nicely-documented format.

On a side note, the constant pool is a perfect example of something made much easier by Scala case classes.

]]> By: david http://www.drmaciver.com/2008/06/lessons-learned-in-class/#comment-352 david Tue, 17 Jun 2008 07:58:07 +0000 http://www.drmaciver.com/?p=169#comment-352 I'm sortof sick and tired of writing wrappers. :-) You end up spending huge amounts of time dealing with the impedance between what you have and what you want, and it costs you in both performance and usability. Also, I'm interested enough in the details of this that I think I'd like to do my own thing. I’m sortof sick and tired of writing wrappers. :-) You end up spending huge amounts of time dealing with the impedance between what you have and what you want, and it costs you in both performance and usability. Also, I’m interested enough in the details of this that I think I’d like to do my own thing.

]]> By: DavidLG http://www.drmaciver.com/2008/06/lessons-learned-in-class/#comment-351 DavidLG Tue, 17 Jun 2008 07:26:43 +0000 http://www.drmaciver.com/?p=169#comment-351 Hi David, What I did for my own Scala bytecode library (for internal use) was to use ASM as a class-file reader/writer, but keep a nice Scala-like representation. I've written code to parse class-files a few times, back in my Java days, and didn't feel like doing it again. ASM has some interesting design goals that I'm not interested in at all; small library size (hence the six different jars totaling 200k so you don't include stuff you don't need), small RAM footprint (visitor pattern), and instrumentation speed (doesn't need to create lots of data structures on the heap, lets you easily leave parts of a class unchanged, doesn't assume maxStack and maxLocals need recalculation from scratch). Once you get around that, it's a pretty nice library to have around; the API is the cleanest I've found. Hi David,

What I did for my own Scala bytecode library (for internal use) was to use ASM as a class-file reader/writer, but keep a nice Scala-like representation. I’ve written code to parse class-files a few times, back in my Java days, and didn’t feel like doing it again.

ASM has some interesting design goals that I’m not interested in at all; small library size (hence the six different jars totaling 200k so you don’t include stuff you don’t need), small RAM footprint (visitor pattern), and instrumentation speed (doesn’t need to create lots of data structures on the heap, lets you easily leave parts of a class unchanged, doesn’t assume maxStack and maxLocals need recalculation from scratch). Once you get around that, it’s a pretty nice library to have around; the API is the cleanest I’ve found.

]]> By: david http://www.drmaciver.com/2008/06/lessons-learned-in-class/#comment-349 david Mon, 16 Jun 2008 19:44:29 +0000 http://www.drmaciver.com/?p=169#comment-349 I've actually read that. The thing is, along with everyone else he basically recommends ASM. Thing about ASM, and most of the other bytecode libraries suitable for my purposes: The visitor pattern gives me hives, and the APIs are really verbose. Basically the objective here is to have a library which can take advantage of Scala's features as much as possible. As such I'm probably better off building it from the ground up than using one of the existing ones. I’ve actually read that. The thing is, along with everyone else he basically recommends ASM.

Thing about ASM, and most of the other bytecode libraries suitable for my purposes: The visitor pattern gives me hives, and the APIs are really verbose.

Basically the objective here is to have a library which can take advantage of Scala’s features as much as possible. As such I’m probably better off building it from the ground up than using one of the existing ones.

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