On 2007-08-14, Chaddaï Fouché <[EMAIL PROTECTED]> wrote: > 2007/8/14, Alexteslin <[EMAIL PROTECTED]>: >> Well, i have tried cons (:) operator but when it passed to foldr doesn't work >> because cons operator operates first character and then the list but the >> foldr argument takes a function (a->a->a). Maybe i am missing the point >> here? >> > > What Aaron was saying was that in this list : > 1 : 2 : 3 : 4 : [] > A fold replaced the cons (:) by another function (and [] by another constant). > > Your problem isn't so easy to do with a foldr, a foldl would be easier > and a foldr1 or foldl1 even better. Are you sure you can't use one of > those other folds ?
The problem with foldl is that you can't easily make it polymorphic because of how the null case is handled. foldl1 and foldr1 are trivial, true. -- Aaron Denney -><- _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
