[Haskell-cafe] Re: Haskell Zippers on Wikibooks: teasing! :)

[Jon Fairbairn]

Matthias Görgens <matthias.goergens at googlemail.com> writes:

>> doesn't make much sense to me yet, although I suspect I can read the mu as a
>> lambda on types?
>
> Not really.  The mu has more to do with recursion.

I'd say it's entirely to do with recursion. It's like the Y combinator
(or fix) for types, though it is combined with a lambda.

mu t . ----t---- is like fix (\t -> ----t----)

-- 
Jón Fairbairn                                 Jon.Fairbairn at cl.cam.ac.uk
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html  (updated 2009-01-31)