{-# LANGUAGE DataKinds, KindSignatures, TypeFamilies, TypeOperators #-}
{-# OPTIONS_GHC -fdefer-type-errors #-}
{-# OPTIONS_GHC -fplugin GHC.TypeLits.Normalise #-}
module ErrorTests where
import Data.Proxy
import GHC.TypeLits
testProxy1 :: Proxy (x + 1) -> Proxy (2 + x)
testProxy1 = id
testProxy1Errors =
["Expected type: Proxy (x + 1) -> Proxy (2 + x)"
,"Actual type: Proxy (2 + x) -> Proxy (2 + x)"
]
type family GCD (x :: Nat) (y :: Nat) :: Nat
type instance GCD 6 8 = 2
type instance GCD 9 6 = 3
testProxy2 :: Proxy (GCD 6 8 + x) -> Proxy (x + GCD 9 6)
testProxy2 = id
testProxy2Errors =
["Expected type: Proxy (GCD 6 8 + x) -> Proxy (x + GCD 9 6)"
,"Actual type: Proxy (x + 3) -> Proxy (x + 3)"
]
proxyFun3 :: Proxy (x + x + x) -> ()
proxyFun3 = const ()
testProxy3 :: Proxy 8 -> ()
testProxy3 = proxyFun3
testProxy3Errors =
["Expected type: Proxy 8 -> ()"
,"Actual type: Proxy ((x0 + x0) + x0) -> ()"
]
proxyFun4 :: Proxy ((2*y)+4) -> ()
proxyFun4 = const ()
testProxy4 :: Proxy 2 -> ()
testProxy4 = proxyFun4
testProxy4Errors =
["Expected type: Proxy 2 -> ()"
,"Actual type: Proxy ((2 * y0) + 4) -> ()"
]
testProxy5 :: Proxy 7 -> ()
testProxy5 = proxyFun4
testProxy5Errors =
["Expected type: Proxy 7 -> ()"
,"Actual type: Proxy ((2 * y1) + 4) -> ()"
]
proxyFun6 :: Proxy (2^k) -> Proxy (2^k)
proxyFun6 = const Proxy
testProxy6 :: Proxy 7
testProxy6 = proxyFun6 (Proxy :: Proxy 7)
testProxy6Errors =
["Expected type: Proxy (2 ^ k0)"
,"Actual type: Proxy 7"
]
proxyFun7 :: Proxy (2^k) -> Proxy k
proxyFun7 = const Proxy
testProxy8 :: Proxy x -> Proxy (y + x)
testProxy8 = id
testProxy8Errors =
["Expected type: Proxy x -> Proxy (y + x)"
,"Actual type: Proxy x -> Proxy x"
]