I still think that getting other authors to use it would be the biggest difficulty. Another concern of mine is that RULEs-based fusion can be fragile; if the type classes prevent fusion from occurring you'll never approach the performance of monomorphic code.
That said, I think this is worth pursuing further because of the benefits you describe. I have spent a great deal of time on exactly this issue with the iteratee package, although my needs there are relatively simple. As a general question to the Haskell community: have you ever attempted to write container-polymorphic code? I'd like to hear about either successes or stumbling blocks. On Wed, Mar 24, 2010 at 12:02 PM, Alberto G. Corona <agocor...@gmail.com> wrote: > Once we have a tree of type classes suitable for all containers, as you > said, theoretically it shouldn't very difficult to incorporate the testing > of different instances for each class used in a program, besides testing > different compilation flags in a genetic algoritm. This latter has already > been done. > http://donsbot.wordpress.com/2010/03/01/evolving-faster-haskell-programs-now-with- > To find automatically the best combination of class implementations and > compilation flags in a single process would be very useful and would save a > lot of manual testing. > > 2010/3/24 John Lato <jwl...@gmail.com> >> >> Hi Alberto, >> >> To some extent this already exists, it's just that nobody uses it. I >> believe it's the approach taken by the Edison libraries. Also the >> ListLike package provides the type classes ListLike, StringLike, and a >> few others. Neither seems to have become very popular despite having >> well-respected authors (Okasaki and Goerzon, respectively). >> >> Some container functions are already provided by other classes, namely >> Foldable, Traversable, and Monoid. >> >> The first bit, creating a tree of type classes suitable for all >> containers, is probably a few hours work. >> >> An automated system to determine the best implementation is >> significantly more difficult; I can't say if the scope would be >> appropriate for SoC. >> >> Best, >> John >> >> > From: "Alberto G. Corona " <agocor...@gmail.com> >> > >> > Just a dream: >> > -separate interface and implementation for all containers, via type >> > classes >> > -develop, by genetic programming techniques + quickcheck, a system that >> > find >> > the best container implementation for a particular program. >> > >> > Is that suitable for a Google Summer of Code project? >> > >> > 2010/3/23 Alberto G. Corona <agocor...@gmail.com> >> > >> > The question can be generalized via type classes: Is there any common >> > set of >> >> primitives encapsulated into a single type class that has instances for >> >> Strings (Data.List) ByteStrings, Data.Text, Lazy bytestrings, Arrays, >> >> vectors and wathever container that can store an boxed, unboxed, packed >> >> unpacked sequence of wathever including chars? All of them have folds, >> >> heads, tails and a lot of common functions with the same name, but >> >> since >> >> there is not a single type class, the library programmer can not >> >> abstract >> >> his code when it is possible, so the library user can chose the >> >> particular >> >> instance for his particular problem. > > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
