Comments for Scala Notes http://www.scala-notes.org Blog about the Scala programming language Sun, 12 Jun 2011 07:27:06 +0000 hourly 1 http://wordpress.org/?v=3.2.1 Comment on Scala 2.9 parallel collections for MandelActors by Jesper http://www.scala-notes.org/2011/05/scala-2-9-parallel-collections-for-mandelactors/#comment-826 Jesper Sun, 12 Jun 2011 07:27:06 +0000 http://www.scala-notes.org/?p=129#comment-826 Hi Chris, Theoretically it could run at twice the speed with two threads, but in practice my program runs about 50% faster on my dual-core machine, and about 100% faster on a quad core machine that I tested it on. There is some synchronization to prevent threads from writing to the same pixel of the output image at the same time, but the rendering is done in such a way that threads should rarely have to wait on each other for that. Note that this program is just one example, it isn't proof that any program will run 50% faster on a dual core machine. The performance with parallel collections is the same as with actors, which I wrote about in an earlier blog post. Hi Chris,

Theoretically it could run at twice the speed with two threads, but in practice my program runs about 50% faster on my dual-core machine, and about 100% faster on a quad core machine that I tested it on. There is some synchronization to prevent threads from writing to the same pixel of the output image at the same time, but the rendering is done in such a way that threads should rarely have to wait on each other for that. Note that this program is just one example, it isn’t proof that any program will run 50% faster on a dual core machine.

The performance with parallel collections is the same as with actors, which I wrote about in an earlier blog post.

]]> Comment on Scala 2.9 parallel collections for MandelActors by Chris http://www.scala-notes.org/2011/05/scala-2-9-parallel-collections-for-mandelactors/#comment-824 Chris Thu, 09 Jun 2011 12:57:28 +0000 http://www.scala-notes.org/?p=129#comment-824 So, the million dollar question... how much faster are the parallel collections on your dual core machine? Very interesting blog! I've added the feed to my reader. So, the million dollar question… how much faster are the parallel collections on your dual core machine?

Very interesting blog! I’ve added the feed to my reader.

]]> Comment on MandelActors by Michael Ernest http://www.scala-notes.org/2011/03/mandelactors/#comment-475 Michael Ernest Sat, 19 Mar 2011 16:53:18 +0000 http://www.scala-notes.org/?p=98#comment-475 Had I understood this distinction between Actors myself when I started to play with Scala, I might have paid more attention. It seemed the author I was reading at the time felt it was either obvious or perhaps too much for someone who didn't already understand. Thank you for making it more apparent! Looking forward to reading back in your blog and then forward. Had I understood this distinction between Actors myself when I started to play with Scala, I might have paid more attention. It seemed the author I was reading at the time felt it was either obvious or perhaps too much for someone who didn’t already understand.

Thank you for making it more apparent! Looking forward to reading back in your blog and then forward.

]]> Comment on A generic interpolate method using type classes by Jesper http://www.scala-notes.org/2010/08/a-generic-interpolate-method-using-type-classes/#comment-60 Jesper Mon, 16 Aug 2010 19:50:41 +0000 http://www.scala-notes.org/?p=73#comment-60 A blog post by Daniel Sobral about the type class pattern in Scala: http://dcsobral.blogspot.com/2010/06/implicit-tricks-type-class-pattern.html A blog post by Daniel Sobral about the type class pattern in Scala:
http://dcsobral.blogspot.com/2010/06/implicit-tricks-type-class-pattern.html

]]> Comment on A generic interpolate method using type classes by acherm http://www.scala-notes.org/2010/08/a-generic-interpolate-method-using-type-classes/#comment-48 acherm Tue, 10 Aug 2010 22:00:01 +0000 http://www.scala-notes.org/?p=73#comment-48 The conclusion is that C++ outperforms Scala on this simple example... *sigh* The conclusion is that C++ outperforms Scala on this simple example… *sigh*

]]> Comment on A generic interpolate method using type classes by Tweets that mention A generic interpolate method using type classes « Scala Notes -- Topsy.com http://www.scala-notes.org/2010/08/a-generic-interpolate-method-using-type-classes/#comment-47 Tweets that mention A generic interpolate method using type classes « Scala Notes -- Topsy.com Tue, 10 Aug 2010 21:58:02 +0000 http://www.scala-notes.org/?p=73#comment-47 [...] This post was mentioned on Twitter by Planet Scala and Planet Lang, Jesper de Jong. Jesper de Jong said: Just posted a new blog post: A generic interpolate method using type classes - http://bit.ly/bD7Lhu [...] [...] This post was mentioned on Twitter by Planet Scala and Planet Lang, Jesper de Jong. Jesper de Jong said: Just posted a new blog post: A generic interpolate method using type classes – http://bit.ly/bD7Lhu [...]

]]> Comment on Strange limitation when importing from different scopes by Jesper http://www.scala-notes.org/2010/07/strange-limitation-when-importing-from-different-scopes/#comment-19 Jesper Sun, 04 Jul 2010 06:02:52 +0000 http://www.scala-notes.org/?p=65#comment-19 You can find the <a href="http://www.scala-lang.org/sites/default/files/linuxsoft_archives/docu/files/ScalaReference.pdf" rel="nofollow">Scala Language Specification</a> on www.scala-lang.org (but it's for 2.7, I don't know if there's a document for 2.8). I haven't checked what it says about importing overloaded methods. You can find the Scala Language Specification on http://www.scala-lang.org (but it’s for 2.7, I don’t know if there’s a document for 2.8). I haven’t checked what it says about importing overloaded methods.

]]> Comment on Strange limitation when importing from different scopes by anon http://www.scala-notes.org/2010/07/strange-limitation-when-importing-from-different-scopes/#comment-17 anon Sat, 03 Jul 2010 21:43:58 +0000 http://www.scala-notes.org/?p=65#comment-17 Is there any substantive difference between partial functions and curried ones? E.g. is it any different to do this: val interpolation = interpolate(2.0, 4.0, _) println(interpolation(0.5)) Honest question. Is there any substantive difference between partial functions and curried ones? E.g. is it any different to do this:

val interpolation = interpolate(2.0, 4.0, _)
println(interpolation(0.5))

Honest question.

]]> Comment on Strange limitation when importing from different scopes by anon http://www.scala-notes.org/2010/07/strange-limitation-when-importing-from-different-scopes/#comment-16 anon Sat, 03 Jul 2010 21:35:44 +0000 http://www.scala-notes.org/?p=65#comment-16 Yes, I did notice that, but I find it odd (and I'd be nice if someone could post a reference to the spec) for a spec to specifically disallow overloaded methods. Typically, there's mention of a signature, and the signature in this case is unique and unambiguous. Yes, I did notice that, but I find it odd (and I’d be nice if someone could post a reference to the spec) for a spec to specifically disallow overloaded methods. Typically, there’s mention of a signature, and the signature in this case is unique and unambiguous.

]]> Comment on Strange limitation when importing from different scopes by Jesper http://www.scala-notes.org/2010/07/strange-limitation-when-importing-from-different-scopes/#comment-14 Jesper Sat, 03 Jul 2010 18:55:34 +0000 http://www.scala-notes.org/?p=65#comment-14 The comment by Martin Odersky in <a href="https://lampsvn.epfl.ch/trac/scala/ticket/2551" rel="nofollow">ticket 2551</a> suggests that this isn't only a case of fixing the problem in the compiler - the language specification would have to be modified to allow this, and for that to happen a SID (Scala Improvement Document) first has to be written. Fixing bugs in specifications is often much harder than fixing bugs in code, in fact it might be easy to fix in the compiler, but because it has to be precisely specified in a document it will still be a lot of work. The comment by Martin Odersky in ticket 2551 suggests that this isn’t only a case of fixing the problem in the compiler – the language specification would have to be modified to allow this, and for that to happen a SID (Scala Improvement Document) first has to be written.

Fixing bugs in specifications is often much harder than fixing bugs in code, in fact it might be easy to fix in the compiler, but because it has to be precisely specified in a document it will still be a lot of work.

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