Fwd: [Haskell-cafe] Haskell custom search engine
Google now lets us create our own custom search engine pages, so I whipped one up for Haskell, I volunteered. Are you planning to add just sites for Haskell-related software, or are research papers included in the scope of this? (Dude, where's my english grammar.) -- syntaxfree ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Announcements list
There should be a separate, moderated Haskell-announcements list. I filter out haskell-cafe into a folder and read it separately from my main inbox, but I'd like to have important announcements directly into my inbox, and haskell@haskell.org still has some chatty questions-and-answers sessions. -- Diego Navarro/syntaxfree ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Shrinking the Prelude: The "categorical" approach
take map for example, and fmap, I don't think they should be named different (fmap is ugly, not suggestive, and conceptually the same). mplus could be renamed (++) (they are conceptually the same Wouldn't this raise the same problems monad comprehensions raise? Worse yet, beginners can't start off with lists -- and understand error messages -- without knowing about monads first! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Mo' comprehensions
I was solving some programming puzzles today[1], and found myself pining for Map comprehensions. Maybe there should be a Comprehensible class that's automatically mapped to comprehension syntax. It's rather odd to have them only for lists. That would be both more general and more elegant than just bringing back monad comprehensions. Is there any obvious reason why this wouldn't work? [1] www.projecteuler.net <-- fun stuff! -- -- Diego Navarro ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Modulo-foo equivalence classes in Haskell?
Watching the questions go by in #haskell, a still fuzzy but possibly pregnant idea popped up in my mind. Someone needed a nubBy function that returned an unique list modulo an arbitrary function foo. Well, in this case it wasn't arbitrary; he had a list of transposable matrices and wanted an unique list of matrices that couldn't be transposed into each other. I'm thinking there are many cases of fooBy functions that have to be constantly rewritten, and also a lot of ugly code by having to constantly add the modulo clauses (like in modular arithmetic). I'm inexperienced with type classes -- I've only done the simplest types and /some/ fundeps -- so I'm wondering what would be the clearest, most general way of having a Modulo-foo Eq class that could be parameterized with a function. The "transposable matrix" example shows how this could be useful for (some limited form) of data compression, but it could make some other forms of "algebraically modular" (this is not a proper term, it's me trying to get thoughts across) business rules, of which modular arithmetic is a special case. Uh, I've probably not expressed myself well enough; I hope I have a shot at trying to explain myself better if questions come up. -- -- Diego Navarro ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Modulo-foo equivalence classes in Haskell?
newtype Y = Y { unY :: X }
instance Eq Y where (==) = foo
nub' :: [X] -> [X]
nub' = map unY . sort . map Y
Yes, I thought of that. I'm really thinking of how I can generalize
the Eq class so I dont have to go around manually "lifting" operations
that are already defined (like operations on integers for modulo-n
rings)
-- Diego Navarro
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Re: [Haskell-cafe] Modulo-foo equivalence classes in Haskell?
Yes, I thought of that. I'm really thinking of how I can generalize the Eq class so I dont have to go around manually "lifting" operations that are already defined (like operations on integers for modulo-n rings) (I do realize it's a lucky chance that the ordinary (+) and (*) work so well on modulo-n rings. Anyway, that's besides the point.) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
