Scrap your Boilerplate

[Johan Jeuring]

> Does the "zipper" fall into this category?
>
> http://haskell.org/wiki/wiki?TheZipper

The zipper is a type-indexed data type, not just a type-indexed=20
function.
See:

R. Hinze, J. Jeuring and A L=F6h. Type-indexed data types. In Eerke A.=20=

Boiten and Bernhard M=F6ller, editors, Proceedings of the 6th=20
International Conference on Mathematics of Program Construction, LNCS=20
2386, pages 148 - 174, 2002, =A9 Springer-Verlag.

-- Johan=