Safe Haskell	Safe-Inferred
Language	Haskell2010

GHC.Tc.Instance.Class

Synopsis

matchGlobalInst :: DynFlags -> Bool -> Class -> [Type] -> TcM ClsInstResult
data ClsInstResult
- = NoInstance
- | OneInst {
  - cir_new_theta :: [TcPredType]
  - cir_mk_ev :: [EvExpr] -> EvTerm
  - cir_what :: InstanceWhat
  }
- | NotSure
data InstanceWhat
- = BuiltinInstance
- | BuiltinEqInstance
- | LocalInstance
- | TopLevInstance {
  - iw_dfun_id :: DFunId
  - iw_safe_over :: SafeOverlapping
  }
safeOverlap :: InstanceWhat -> Bool
instanceReturnsDictCon :: InstanceWhat -> Bool
data AssocInstInfo
- = NotAssociated
- | InClsInst {
  - ai_class :: Class
  - ai_tyvars :: [TyVar]
  - ai_inst_env :: VarEnv Type
  }
isNotAssociated :: AssocInstInfo -> Bool

Documentation

matchGlobalInst :: DynFlags -> Bool -> Class -> [Type] -> TcM ClsInstResult Source #

data ClsInstResult Source #

Constructors

NoInstance
OneInst
Fields cir_new_theta :: [TcPredType] cir_mk_ev :: [EvExpr] -> EvTerm cir_what :: InstanceWhat
NotSure

Instances

Instances details

Outputable ClsInstResult Source #
Instance details Defined in GHC.Tc.Instance.Class Methods ppr :: ClsInstResult -> SDoc Source #

data InstanceWhat Source #

Constructors

BuiltinInstance
BuiltinEqInstance
LocalInstance
TopLevInstance
Fields iw_dfun_id :: DFunId iw_safe_over :: SafeOverlapping

Instances

Instances details

Outputable InstanceWhat Source #
Instance details Defined in GHC.Tc.Instance.Class Methods ppr :: InstanceWhat -> SDoc Source #

safeOverlap :: InstanceWhat -> Bool Source #

instanceReturnsDictCon :: InstanceWhat -> Bool Source #

data AssocInstInfo Source #

Extra information about the parent instance declaration, needed when type-checking associated types. The Class is the enclosing class, the [TyVar] are the scoped type variable of the instance decl. The VarEnv Type maps class variables to their instance types.

Constructors

NotAssociated
InClsInst
Fields ai_class :: Class ai_tyvars :: [TyVar] The scoped tyvars of the instance Why scoped? See bind_me in `checkConsistentFamInst` ai_inst_env :: VarEnv Type Maps class tyvars to their instance types See Note [Matching in the consistent-instantiation check]

isNotAssociated :: AssocInstInfo -> Bool Source #