fmap = map 其他Functor实例的例子包括树: -- 一个简单的二叉树 data Tree a = Leaf a | Fork (Tree a) (Tree a) instance Functor Tree where fmap f (Leaf x) = Leaf (f x) fmap f (Fork
Stechmann, A.; Cavalier-Smith, T. Rooting the eukaryote tree by using a derived gene fusion. Science. 2002, 297: 89–91. ISSN 0036-8075. 引文使用过时参数coauthors