Peter Verswyvelen wrote:
After my colleague explained me about zippers and how one could derive the datatype using differential rules, I had to read about it.
So I started reading http://en.wikibooks.org/wiki/Haskell/Zippers#Mechanical_Differentiation
This page contains the sentence: *"For a systematic construction, we need to calculate with types. The basics of structural calculations with types are outlined in a separate chapter **Generic Programming*http://en.wikibooks.org/w/index.php?title=Haskell/Generic_Programming&action=edit&redlink=1 * and we will heavily rely on this material"* * * However, the generic programming link does not exist yet :-)
A clear case of laziness on the author's part... wait, that would be me. :-O In any case, contributions to the wikibook would be most welcome. ;-) For now, I'd recommend Generic Programming: An introduction http://www.cse.chalmers.se/~patrikj/poly/afp98/ It's a bit verbose at times, but you only need the first few chapters to get an idea about polynomial functors (sums and pairs) and mu . Regards, apfelmus -- http://apfelmus.nfshost.com