"Richard O'Keefe" <o...@cs.otago.ac.nz> writes: > There's a long-known technique in functional languages > where > [x1,...,xn] => \tail -> x1:...xn:tail > xs ++ ys => f . g > xs => f [] > > A correspondent mentioned to me that he couldn't find a reference > to the idea (which I gather he had independently rediscovered). > I know I've read about it somewhere. Can anyone provide a reference?
They're called difference lists: http://hackage.haskell.org/packages/archive/dlist/latest/doc/html/Data-DList.html They allow O(1) snoc and append. I use them all the time! G -- Gregory Collins <g...@gregorycollins.net> _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
