[Haskell-cafe] Simple quirk in behavior of `mod`

2009-07-21 Thread Nathan Bloomfield
/message/5dmehw4lhu56x4zw from 2002 is the most relevant one I could find; it is suggested there that n `mod` 0 should be an error. Thanks all- Nathan Bloomfield *- The mod function is defined in the Integral class, and I'm not even sure how to interpret that. It looks kind of like a Euclidean domain

Re: [Haskell-cafe] Re: gcd

2009-05-03 Thread Nathan Bloomfield
with this property is 0, which can be proved using the essential uniqueness of prime factorizations and infinitude of primes. So having gcd(0,0) = 0 isn't just useful, it's the correct thing to do. I hope that didn't use too many long words. :) -Nathan Bloomfield Grad Assistant, University

Re: [Haskell-cafe] Re: gcd

2009-05-03 Thread Nathan Bloomfield
to consider gcds in rings that otherwise have no natural order- such as rings of polynomials in several variables, group rings, et cetera. Nathan Bloomfield On Sun, May 3, 2009 at 11:16 AM, Achim Schneider bars...@web.de wrote: Nathan Bloomfield nblo...@gmail.com wrote: The greatest in gcd

[Haskell-cafe] Grokking zippers

2009-03-20 Thread Nathan Bloomfield
exactly is the derivative of a functor at an object, in the direction of some arrow? I'm interested in studying this concept in more depth, but I can't find a definition to start with. Any pointers to good books or papers would be greatly appreciated. :) Thank you all- Nathan Bloomfield

Re: Improved documentation for Bool (Was: [Haskell-cafe] Comments from OCaml Hacker Brian Hurt)

2009-01-18 Thread Nathan Bloomfield
That's a great start, but coproduct is still pretty scary. Why not refer to it as OneOrTheOtherButNotBothDataConstructor? -Nathan Bloomfield On Sun, Jan 18, 2009 at 11:32 AM, Sterling Clover s.clo...@gmail.comwrote: This is a great effort, but the root of the problem isn't just poor

Re: [Haskell-cafe] OT: representations for graphs

2008-12-19 Thread Nathan Bloomfield
(Forgot to send to haskell-cafe- sorry Alistair!) Martin Erwig wrote a paper [1] that defines an inductive graph type and implements some common algorithms with it. Also, it isn't very Haskellish but if you can label your nodes with an instance of Ix you might be able to use an Array to get

Re: [Haskell-cafe] Time for a new logo?

2008-12-16 Thread Nathan Bloomfield
logo. My biggest concern is that to someone not already familiar with Haskell syntax, it might be confusing. (That may or may not be an actual problem.) Nathan Bloomfield ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org

[Haskell-cafe] Parsec and type level numerals

2008-12-13 Thread Nathan Bloomfield
in general, so I apologize if this is a silly question. (Parsec is very impressive, by the way.) Thanks- Nathan Bloomfield University of Arkansas, Fayetteville ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo

Re: [Haskell-cafe] Origins of '$'

2008-12-08 Thread Nathan Bloomfield
, then. Hans Slightly off topic, but the A^B notation for hom-sets also makes the natural isomorphism we call currying expressable as A^(BxC) = (A^B)^C. Nathan Bloomfield ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org

Re: [Haskell-cafe] Re: universal algebra support in Haskell?

2008-10-23 Thread Nathan Bloomfield
to cc haskell-cafe- sorry DavidA!) Nathan Bloomfield ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Writing a function isPrime using recursion.

2008-10-15 Thread Nathan Bloomfield
At the risk of doing someone's homework... A naive solution is to do trial division by all integers from 2 up to sqrt n. {- isPrime :: Integer - BoolisPrime n | n 2 = False | otherwise = f 2 n where f k n = if k isqrt then True else undefined -- exercise for the reader -}

Re: [Haskell-cafe] Re: Best book/tutorial on category theory and its applications

2008-07-30 Thread Nathan Bloomfield
If you want to see a human being explain some categorical ideas, there is a nice (and growing) collection of video mini-tutorials on youtube by the Catsters. http://www.youtube.com/user/TheCatsters -Nathan Bloomfield (I first sent this just to Pierre by accident - sorry

[Haskell-cafe] FPers in Northwest Arkansas?

2008-07-25 Thread Nathan Bloomfield
Greetings, Haskell-cafe. I am interested in joining or starting a functional programming interest group in my area. Are there any haskellers in the Northwest Arkansas region? Nathan Bloomfield ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http

[Haskell-cafe] A question about algebra and dependent typing

2008-07-14 Thread Nathan Bloomfield
There's something I want to do with Haskell, and after tinkering for a while I think it's not possible. Before giving up entirely, I thought I'd try this mailing list. I'm working on an abstract algebra library, using the types are sets strategy. For the algebraists out there, I'm trying to