Re: DeriveFoldable treatment of tuples is surprising

On 2017-03-21 21:34, David Feuer wrote:

This seems much too weird:

*> :set -XDeriveFoldable *> data Foo a = Foo ((a,a),a) deriving Foldable *> length ((1,1),1) 1 *> length $ Foo ((1,1),1) 3

This is not unique to tuples, consider: > :set -XDeriveFoldable > data Foo a = Foo [[a]] deriving Foldable > length [[1,2]] 1 > length $ Foo [[1,2]] 2 Twan