hy-lists

Copperbox revision 939.

I've started a new library / package for the minor lists snoc-list, one-list, ...

The salient feature of the library is that I'm trying to implement the list manipulations (filter, etc.) as hylomorphisms converting snoc-lists or one-lists to regular lists during the manipulation. There is a conceptual distinction between the construction of the inital snoc- and one-lists (which involves some restriction - non-empty for one-lists, suffixing for snoc-lists) and their subsequent manipulation.

The next step is seeing if non-empty one-lists work for the Multi constructor inside Wumpus's picture type.