Re: [Haskell-cafe] [Haskell-beginners] For class Monoid; better names than mempty & mappend might have been: mid (mident) & mbinop
On 24 Jul 2011, at 19:19, KC wrote: > I like the following but again "+" denotes addition and not a general > binary operation. > > >> I personally often define the alias: >> >> (<+>) = mappend > > A lot of math books use "+" or "x" enclosed in a circle to indicate > that the usual meaning of "+" nor "x" is intended for the meaning of > the binary operation. Er no. Both symbols have extremely precise meanings. $\oplus$ is the direct sum of two modules and $\otimes$ is their tensor product. Personally, I wish, given that an additive monad is a kind of monoid, that the names for the zero and addition operations for the two classes were the same. That said, I am not especially happy with mzero and madd, given that their implication, that the monoid is abelian, is generally false. > > I can't figure out if this would compile, the inside "()" representing a > circle. > > ((+)) = mappend > > > > > It would be easier for beginners to "grok". > >> I don't think so... but while we're at it, what's with that weird name >> "Monoid" anyway, let alone "Functor", "Monad", etc.? ;-) > > Ivan: I had thought those were words expressing valid mathematical concepts. > > In order to find similarities between apparently different operations > & data one wants to reason abstractly; similar to mathematics. > > -- > -- > Regards, > KC > > ___ > Beginners mailing list > beginn...@haskell.org > http://www.haskell.org/mailman/listinfo/beginners ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cloud Haskell
I'm using it as the basis for a lightweight distributed generalised MapReduce framework for Haskell, which basically turns out to be a framework for distributed monads. I haven't started serious work yet, but expect to in the next few days, and so would be interested to share experiences. J Julian Porter julian.por...@porternet.org http://www.porternet.org On 23 Jul 2011, at 11:03, Tim Cowlishaw wrote: > On Fri, Jul 22, 2011 at 4:11 PM, Tom Murphy wrote: > >> Is anyone using Cloud Haskell yet? I'm really excited by the >> possibilities. > > Hello there! I'm currently looking at the possibility of incorporating > it into my masters thesis project (A Haskell EDSL for agent-based > simulation), but haven't yet implemented the part of the project > that'll use it. I'd also be interested in anyone else's experiences > with it as it seems like a fairly young project, and will try and > write up some of my own once I've got a bit further with it! > > Thanks, > > Tim > > ___ > 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] The Lisp Curse
> ultimately the ideal is to end up with one library that solves the problem > well, which everybody can use. > > Nonsense. One library that everyone can use with either end up being so small in functionality that it's actually useless, or so general that either it requires tons and tons of boilerplate just to use it at all, or it's really about eight libraries rolled into one and so impossible to find your way around. Whichever, it's not good. The sweet spot is at the point of maximum tension between generality and simplicity. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Problems with haskell98 package in GHC
> > Looks like you've done a global install and thus have overwritten the > original. I'm afraid that means you have to reinstall GHC, I know of no way > to fix it. Thank you for the explanation. Fortunately, the old version was still there in its own folder, so was able to unregister the new one and re-expose the old. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Problems with haskell98 package in GHC
Hello, I recently tried upgrading the package haskell98 to version 1.1.0.1. Two things went wrong: (1) Some of the time the build failed because it said it couldn't build time-1.2.0.4 (which I already had installed) (2) Even when I finally managed to get it to build and install, compiling code led to this error message: Bad interface file: /usr/local/lib/haskell98-1.1.0.1/ghc-6.12.3/IO.hi Something is amiss; requested module haskell98:IO differs from name found in the interface file haskell98-1.1.0.1:IO I'm running GHC version 6.12.3. Any help much appreciated. Julian Porter julian.por...@porternet.org http://about.me/julian.porter ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
