Moduleoptics-core-0.4.1.1Haskell2010

Optics.Internal.Magic

This module is intended for internal use only, and may change without warning in subsequent releases.

2 classes

Packageoptics-core-0.4.1.1
Exports2
LanguageHaskell2010
LicenceBSD-3-Clause
SourceMagic.hs

class

class Dysfunctional (field :: k) (k6 :: k1) (s :: k2) (t :: k3) (a :: k4) (b :: k5) | field s -> k6 t a b, field t -> k6 s a b

How about a magic trick? I'm gonna make the coverage condition disappear.

Instances1Dysfunctional

TypeInferenceLoop "Type inference for the local binding failed. Write the type" "signature yourself or disable monomorphism restriction with" "NoMonomorphismRestriction LANGUAGE pragma so GHC infers it." field k7 s t a b => Dysfunctional field k7 s t a bDefined in optics-core-0.4.1.1 · Optics.Internal.Magic
Show something useful when type inference goes into a loop and stops with "reduction stack overflow" message (sometimes happens when trying to infer types of local bindings when monomorphism restriction is enabled).

class

class TypeInferenceLoop (msg1 :: k) (msg2 :: k1) (msg3 :: k2) (field :: k3) (k9 :: k4) (s :: k5) (t :: k6) (a :: k7) (b :: k8) | field s -> k9 t a b, field t -> k9 s a b

Instances1TypeInferenceLoop

TypeInferenceLoop msg1 msg2 msg3 field k10 s t a b => TypeInferenceLoop msg1 msg2 msg3 field k10 s t a bDefined in optics-core-0.4.1.1 · Optics.Internal.Magic
Including the instance head in the context lifts the coverage condition for all type variables in the instance. A dirty trick until we have https://github.com/ghc-proposals/ghc-proposals/pull/374 and can do it properly.