blob: 184d5df1f077989d01ec2149a486f77d3aa41840 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
{-# LANGUAGE FlexibleInstances, UndecidableInstances #-}
module Main where
main :: IO ()
main = do
let k1 = func1 1 :: Int
print $ show k1
let k2 = outer :: Int
print $ show k2
outer :: Class3 a => a
outer = func1 1
class Class1 a where
func1 :: Int -> a
class Class1 a => Class2 a where
func2 :: Int -> a
class Class2 a => Class3 a where
func3 :: Int -> a
instance Class1 Int where
func1 = id
instance (Class1 a, Class3 a) => Class2 a where
func2 = func3
instance Class3 Int where
func3 = id
--
-- "1"
-- tests: <<loop>>
|
