Tamas K Papp wrote:
On Sun, Sep 03, 2006 at 12:47:45PM +0400, Bulat Ziganshin wrote:
i also suggest you to start write some library. there is enough useful libs that are still bnot implemented because lack of time (and insterest in such simple code) on side of more experienced programmers. i once proposed you to write strings library, another interesting and useful thing will be gzip/bzip2-lib bindings
Bulat,
I would be happy to write a strings library, I just don't know that it is supposed to do... (I have no CS education, only math/economics). If you show me the specifications or documentation in another language, I would write one as practice.
What about a library for interval arithmetic [1]? I'd imagine it could start something like: data Interval a = Interval !a !a deriving (Eq, Show) instance Num a => Num (Interval a) where Interval llow lhigh + Interval rlow rhigh = Interval (min llow rlow) (max lhigh rhigh) The Interval type would probably need to explicitly represent several kinds of intervals eg (-infinity, x] etc and there are some tricky issues about what to do with the operations whose result sometimes needs to be represented by more than one interval to be useful such as division by an interval containing zero eg you might want to use a list of intervals to deal with these cases: instance Num a => [Interval a] where ... ie [Interval 5 5] / [Interval -1 1] = [FromNegInfinityTo -5, ToPosInfinityFrom 5] though using a list may make things too slow (ideally it would be nice to have interval arithmetic that's as fast as normal floating point arithmetic - is this possible?) Alternatively, these cases could just be undefined though that might limit the usefulness of the lib. Another extremely useful thing would be a symbolic math library with a BSD (or LGPL) license... And yet another extremely useful thing would be a good library for numerical computations (there is GSLHaskell but that's licensed under GPL so there still seems to be a gap for something similar using LGPL or BSD). In general if you look at http://www.haskell.org/haskellwiki/Libraries_and_tools/Mathematics there appear to be many extremely useful libs already written, but unfortunately a lot of them are not BSD compatible so I think there is a huge gap for math related libs that people can use for commercial projects. Anyway just an idea :-), Brian. [1] http://en.wikipedia.org/wiki/Interval_arithmetic -- Logic empowers us and Love gives us purpose. Yet still phantoms restless for eras long past, congealed in the present in unthought forms, strive mightily unseen to destroy us. http://www.metamilk.com