Re: [Haskell-cafe] Possible Improvements

dons:

* Full strictness == teh suckness. * Mixed lazy and strict == flexible and efficient data types.

Makes me wonder why Map is strict in the spine,

data Map k a = Tip | Bin {-# UNPACK #-} !Size !k a !(Map k a) !(Map k a)

Spencer points out that being sized-balanced, subtree sizes must be computed on insertion, so may as well make the structure spine strict anyway. -- Don