I think Data.Unique is horrible and should be banned. It encourages a global variable style of programming that will just bite you in the end.
-- Lennart On Mon, Mar 30, 2009 at 8:40 PM, Jeremy Shaw <jer...@n-heptane.com> wrote: > At Mon, 30 Mar 2009 20:29:14 +0100, > Andrew Coppin wrote: >> >> Maybe I'm just being blind here, but I don't see a monad transformer (or >> even a monad) in the standard libraries for producing "unique" values. >> Have I missed something? > > There is Data.Unique > > http://www.haskell.org/ghc/docs/latest/html/libraries/base/Data-Unique.html > > Not sure if that is suitable for your needs. Obviously it doesn't do > everything that one might desire. > >> Related, I don't see a monad for gradually consuming input. We've got >> the Reader monad, but that appears to just give you global access to a >> single monolithic value. >> >> (I guess ultimately you can build all these specialised monads out of >> the general State monad if you want. I'm just surprised they're not >> already defined somewhere...) > > I have written a Consumer monad, but I never uploaded it to hackage, > because, as you say, it seemed like it should just be a specialized > version of the State monad?. > > It's here: > > http://www.n-heptane.com/nhlab/repos/haskell-consumer/ > > If people think it is actually valuable, I'll upload it. I would be > interested in hearing some debate about what I wrote, versus just > implementing it on top of the State monad, if anyone has something to > say about that. > > Since the Reader and Writer monads could be implemented as specialized > version of State, maybe that is an argument for implementing Consumer > as I have? (Also, I get the feeling this Consumer monad already exists > somewhere else?). > > - jeremy > _______________________________________________ > 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