blob: 58b9ead731704e0a94a09103118d5b6b5c95d3a1 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies,
FlexibleInstances #-}
-- !!! Functional dependencies
-- This broke an early impl of functional dependencies
-- (caused a panic)
module ShouldCompile where
class Foo r a | r -> a where
foo :: r -> a
instance Foo [m a] (m a)
bad:: Monad m => m a
bad = foo bar
bar:: [m a]
bar = []
|
