mc25.hs:9:10: error:
No instance for (Functor t1) arising from a use of ‘fmap’
Possible fix:
add (Functor t1) to the context of
a type expected by the context: (a -> b) -> t1 a -> t1 b
or the inferred type of z :: [t1 t]
In the expression: fmap
In a stmt of a monad comprehension: then group by x using take
In the expression: [x | x <- [1 .. 10], then group by x using take]
mc25.hs:9:46: error:
Couldn't match type ‘a -> t’ with ‘Int’
Expected type: (a -> t) -> [a] -> [t1 a]
Actual type: Int -> [t1 a] -> [t1 a]
Relevant bindings include z :: [t1 t] (bound at mc25.hs:9:1)
In the expression: take
In a stmt of a monad comprehension: then group by x using take