I note that you didn't address the suggestion of a zipper.
Günther Schmidt wrote: > Dan Weston schrieb: >> Unless I'm missing something in your description, why not >> >> data Container a = Single a | Many a a [a] >> > > Hi Dan, > > the above solution would still allow to construct, for instance, > > Many 5 42 [] :: Container Int > > The reason why I'm trying to find the design for a data structure in > which this would not even be possible is to be able to avoid writing > additional "bookkeeping" code into the functions that operate on the > structure, ie. the lookups, inserts, delete etc. > > Günther > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > -- Tony Morris http://tmorris.net/ _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe