Re: [Haskell-cafe] bitSize
Am 25.08.2011 um 19:57 schrieb Andrew Coppin: Is there a way to actually determine how many bits are in an Integer? occupiedBits :: Integer - Int occupiedBits = (+1) . truncate . logBase 2 . (+1) Caveat: untested :-) Cheers, Gabor ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] pthread_kill missing?
Hi all, I'd like to send a signal from the main thread to a forkOS-ed thread in GHC. The former should use raiseSignal and the second should sit in awaitSignal. I figured that the posix functionality in the unix-2.3 library does not cover this case. I would have expected that blocking/sending/receiving signals would utilize the pthread_* routines. This does not seem to be the case. Any idea when these will be available? Thanks in advance, cheers, Gabor PS: I guess some of you will say, use condition variables. But that won't answer my question :-) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] pthread_kill missing?
Am 18.11.2009 um 14:15 schrieb Svein Ove Aas: On Wed, Nov 18, 2009 at 2:03 PM, Gabor Greif ga...@mac.com wrote: PS: I guess some of you will say, use condition variables. But that won't answer my question :-) Actually, I was going to say use throwTo. Is there som reason you have to use the POSIX routines directly instead of using native haskell exceptions? Because I'd like to eventually send signals from outside (e.g. a shell) too. This is in fact a stripped-down version of a real program written in C mainly to demonstrate how much easier it is to get the same functionality in Haskell. How much work would it be to add the pthread signal blocking/sending facility to the unix library? Cheers, Gabor -- Svein Ove Aas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Parameterisations of Monads
Am 05.02.2008 um 21:27 schrieb Dan Weston: Matthew, Your SuperMonad seems remarkably similar to Gabor Greif's Thrist datatype [1,2] reported only six days ago on this list [3]. Can you compare/contrast your class approach with his polymorphic type approach? Or have I completely confused the two because of the similar kind of their arguments? data Thrist :: (* - * - *) - * - * - * where Nil :: Thrist p a a Cons :: p a b - Thrist p b c - Thrist p a c data Arrow' :: (* - * - *) - * - * - * where Arr :: Arrow a = a b c - Arrow' a b c First :: Arrow a = Arrow' a b c - Arrow' a (b, d) (c, d) For the record, I have done the monad into thrist embedding now: http://heisenbug.blogspot.com/2008/02/embeddings-part-two-monad- thrist.html Will start pondering about mfix and restricted monads now. Cheers, Gabor ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Relevance and applicability of category theory
Am 31.01.2008 um 01:23 schrieb [EMAIL PROTECTED]: 3. I believe the documentation stating that Haskell arrows are a generalization of Haskell monads, but arrows are a categorical thing too and in that context bear a much more distant relationship to monads. Does a Haskell arrow have Hask as domain and codomain? Or is one particular element in Hask its domain and possibly another its codomain? Those are not at all the same thing. Without being able to dive into this matter now, I just want to say that both the Haskell monads and arrows can be generalized to something I call a thrist, which appears to be the moral equivalent of a free category. The underlying category is obtained by a two-parameter GADT (defining the morphisms) and the domains and codomains of its members (which are Haskell types) being the objects. Here is my blog entry that motivates the concept a bit: http://heisenbug.blogspot.com/2007/11/trendy-topics.html Cheers, Gabor ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Relevance and applicability of category theory
Am 31.01.2008 um 18:13 schrieb Dan Weston: Even though you cannot dive into this matter now, maybe when you get time you can update your blog with an explicit embedding of Haskell monads and arrows in your Thrist construction. Concrete examples will help me (and probably others) more quickly see the novelty, increased generality, and usefulness of a Thrist. Okay, I took my time and came up with: http://heisenbug.blogspot.com/2008/01/embeddings-part-one-arrow- thrist.html Comments welcome. Also, although you say that thrists are the moral equivalent of a free category, it appears (at least to me) possible that the first Thrist argument enables the construction of a restricted domain monad, e.g. (Eq a = Set a) monad. Is this so? Hmmm, not sure what you asking for. If you have a monad instance Set a that has Eq a attached, this already would do what you want, no? An example would help me to understand... Dan Cheers, Gabor ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Editor
Am 23.05.2007 um 00:20 schrieb Ashley Yakeley: I don't suppose you're familiar with the Dylan programming language, or more to the point, have looked at the IDE that Apple included in their original implementation of the language (around 1993 or so)? Characteristic of Apple of that time, the UI was both highly innovative and a joy to use. It was based around browsers, where each browser had a subject (such as a project, module, definition etc.) and an aspect (such as contents of, errors in, references to, direct methods of etc.). Browsers could be linked so that the selection in one browser became the subject in another. This made it very easy to navigate your project. All code was stored in a database rather than as text files, and individual code definitions were separate objects in the browsers rather than pieces of text in a big file. Info w/ screenshots: http://osteele.com/museum/apple-dylan http://wiki.opendylan.org/wiki/view.dsp?title=Apple%20Dylan Needless to say, this goes in rather the opposite UI direction to the Ctrl-M Ctrl-Meta-Z esc :edit qx approach to editors that some people prefer. Dylan's not a bad language, and there are open source implementations available for Gnu/Linux. But if you want to check out Apple's IDE, you'll really need a 68K Mac, as the PPC version is very buggy and I don't think the 68K version will run in PPC. Michael's blog: http://snakeratpig.blogspot.com/2007/02/road-to-haskell.html Dylan and Haskell are very similar in the multiple-dispatch (a haskeller would call that pattern matching on several arguments) respect. Cheers, Gabor PS: Btw, the Apple Dylan IDE works well on PPC if you apply a patch that was issued by Digitool shortly after the initial port of the IDE to PPC. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Any Haskellers anywhere?
Am 06.05.2007 um 03:52 schrieb Rob Hoelz: Sounds like a good idea to me. I'd like to see if any Haskellers are in Madison. Doesn't Google have a service for visualizing locations on a map? The wiki could point there, for example... Gabor ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
