9 Aug
2015
9 Aug
'15
6:53 a.m.
Yi Lu is spot on right: 1. xs :: [Int] Prelude> []:[1] <interactive>:2:1: Non type-variable argument in the constraint: Num [t] (Use FlexibleContexts to permit this) When checking that ‘it’ has the inferred type it :: forall t. Num [t] => [[t]] 2. xs :: [[Float]] Prelude> []:[[0.1]] [[],[0.1]] 3. xs :: [[[Char]]] Prelude> []:[[['a']]] [[],["a"]] 4. xs :: [[[[Bool]]]] Prelude> []:[[[[True]]]] [[],[[[True]]]]