Thank you, Adam, for I didn't know about paczesiowa's article. That will be useful for me.
What I was trying to make is a zipWithN that takes the zipper function as its "last" argument, not the first. This is because in my applications the zipper functions tend to be complicated lambdas, as illustrated in [1] . Since we live in curried world where all functions are superficially unary, to define the "last" argument, and to implement forZN, needs extra work than to implement zipWithN, I believe [2] . I'm interested how much we can make these two share their internal mechanisms. [1] https://github.com/nushio3/practice/blob/master/free-objects/zipf-05.hs [2] https://groups.google.com/forum/?fromgroups=#!topic/haskell-cafe/-e-xaCEbd-w 2012/12/6 adam vogt <vogt.a...@gmail.com>: > On Wed, Dec 5, 2012 at 12:12 AM, Takayuki Muranushi <muranu...@gmail.com> > wrote: >> Dear everyone, >> >> I have a code >> https://github.com/nushio3/practice/blob/master/instance-inference/zipf-11-1.hs >> >> that produces a type-error when I remove a type signature. >> https://github.com/nushio3/practice/blob/master/instance-inference/zipf-11.hs > > Hi Takayuki, > > The ghc manual sections about the extensions are a good place to > start. Also check out http://okmij.org/ftp/Haskell/ > > I think you are expecting forZN to be able to use the number of -> in > the function(s) supplied to decide how many lists to take, as done > here: http://paczesiowa.blogspot.ca/2010/03/generalized-zipwithn.html > > Replacing the [] container used in the above zipWithN with a > `Data.Key.Zip v => v' that is the same for all of the arguments might > be straightforward. But there are a lot of type signatures that have > to add that parameter, and maybe that will interfere with the > incoherent instance business going on. > > Adam > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe -- Takayuki MURANUSHI The Hakubi Center for Advanced Research, Kyoto University http://www.hakubi.kyoto-u.ac.jp/02_mem/h22/muranushi.html _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
