Comments on: Brian’s functional brain in lisp http://ryepup.unwashedmeme.com/blog/2009/10/04/brians-functional-brain-in-lisp/ mostly tech, mostly rants Tue, 07 Feb 2012 18:44:56 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: ryan http://ryepup.unwashedmeme.com/blog/2009/10/04/brians-functional-brain-in-lisp/comment-page-1/#comment-32516 ryan Mon, 05 Oct 2009 22:01:36 +0000 http://ryepup.unwashedmeme.com/blog/?p=135#comment-32516 @Christophe: ahh, ok, that makes more sense. @Tom: Excellent point, I totally agree. That means it's only a matter of time before clojure developers build up and share idiomatic wrapper libs. @Lau: Interesting optimizations. In my previous experience with using lisp and SDL, the actual drawing was always my bottleneck, so I didn't bother with profiling. I'm curious if I can add type declarations and get any noticeable improvement. RE syntactic sugar, there are a few lisp libraries that add that sort of thing to the language, and they have mixed adoption. I prefer adding small functions (like get-cell / set-cell) to abstract things a little and I think it makes my code more readable. RE STM, I vaugely recall some ant simulation example from a while back, and someone wrote it in lisp, but there seemed to be a major difference based on STM that I didn't grok at the time. I suspected that might be the case here, too, but I didn't see any STM in use. @Christophe: ahh, ok, that makes more sense.

@Tom: Excellent point, I totally agree. That means it’s only a matter of time before clojure developers build up and share idiomatic wrapper libs.

@Lau: Interesting optimizations. In my previous experience with using lisp and SDL, the actual drawing was always my bottleneck, so I didn’t bother with profiling. I’m curious if I can add type declarations and get any noticeable improvement.

RE syntactic sugar, there are a few lisp libraries that add that sort of thing to the language, and they have mixed adoption. I prefer adding small functions (like get-cell / set-cell) to abstract things a little and I think it makes my code more readable.

RE STM, I vaugely recall some ant simulation example from a while back, and someone wrote it in lisp, but there seemed to be a major difference based on STM that I didn’t grok at the time. I suspected that might be the case here, too, but I didn’t see any STM in use.

]]> By: Lau Jensen http://ryepup.unwashedmeme.com/blog/2009/10/04/brians-functional-brain-in-lisp/comment-page-1/#comment-32512 Lau Jensen Mon, 05 Oct 2009 11:40:23 +0000 http://ryepup.unwashedmeme.com/blog/?p=135#comment-32512 Hey Ryan, Interesting translation. I've just added a new blog post covering some optimization strategies for Brians Brain, you can have a look if you like. (http://tinyurl.com/ydhq8wf) RE your observations: 5. It's not syntax, it's syntactic sugar so if it doesn't help you, just don't use it. 6. STM not used at all, it's a concurrency semantic for synchronized change, see the Scala vs Clojure part 2 or Dining Philosophers post for more on this. Best regards, Lau Hey Ryan,

Interesting translation. I’ve just added a new blog post covering some optimization strategies for Brians Brain, you can have a look if you like. (http://tinyurl.com/ydhq8wf)

RE your observations:
5. It’s not syntax, it’s syntactic sugar so if it doesn’t help you, just don’t use it.
6. STM not used at all, it’s a concurrency semantic for synchronized change, see the Scala vs Clojure part 2 or Dining Philosophers post for more on this.

Best regards,
Lau

]]> By: Tom Emerson http://ryepup.unwashedmeme.com/blog/2009/10/04/brians-functional-brain-in-lisp/comment-page-1/#comment-32510 Tom Emerson Mon, 05 Oct 2009 10:54:44 +0000 http://ryepup.unwashedmeme.com/blog/?p=135#comment-32510 In response to your observations about Java interop (2 and 3): think of the interface to Java as Clojure's FFI. Whenever you interface Lisp to a non-Lisp language you end up with a capacitance mismatch that makes the interaction a bit awkward: you can say the same thing (for example) in Clozure Common Lisp's Objective-C bridge. Interacting with the Java GUI classes is particularly ugly because these APIs are heavily object-oriented and rely on interfaces. However, once you grasp the constructs it isn't any more awkward than using CL-FFI, IMHO. When I utilize Java libraries in my non-trivial Clojure programs I usually write an idiomatic wrapper around the "low-level" interface. Consider the Penumbra interface to OpenGL: http://github.com/ztellman/penumbra In response to your observations about Java interop (2 and 3): think of the interface to Java as Clojure’s FFI. Whenever you interface Lisp to a non-Lisp language you end up with a capacitance mismatch that makes the interaction a bit awkward: you can say the same thing (for example) in Clozure Common Lisp’s Objective-C bridge.

Interacting with the Java GUI classes is particularly ugly because these APIs are heavily object-oriented and rely on interfaces. However, once you grasp the constructs it isn’t any more awkward than using CL-FFI, IMHO.

When I utilize Java libraries in my non-trivial Clojure programs I usually write an idiomatic wrapper around the “low-level” interface. Consider the Penumbra interface to OpenGL: http://github.com/ztellman/penumbra

]]> By: Christophe Grand http://ryepup.unwashedmeme.com/blog/2009/10/04/brians-functional-brain-in-lisp/comment-page-1/#comment-32508 Christophe Grand Mon, 05 Oct 2009 08:50:25 +0000 http://ryepup.unwashedmeme.com/blog/?p=135#comment-32508 Hi Ryan, Interesting read. On a minor point I think you misunderstood some part of the clojure code: it doesn't use a single long vector but a seq of seqs (which were initialized with a vector of vectors) -- each nested seq being a row. Thus the parallelism is per row and not per cell. (The inner map isn't replaced by pmap.) Hi Ryan,

Interesting read. On a minor point I think you misunderstood some part of the clojure code: it doesn’t use a single long vector but a seq of seqs (which were initialized with a vector of vectors) — each nested seq being a row. Thus the parallelism is per row and not per cell. (The inner map isn’t replaced by pmap.)

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