Safe Haskell | None |
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InstEnv
- type DFunId = Id
- data OverlapFlag
- = NoOverlap { }
- | OverlapOk { }
- | Incoherent { }
- type InstMatch = (ClsInst, [DFunInstType])
- type ClsInstLookupResult = ([InstMatch], [ClsInst], Bool)
- data ClsInst = ClsInst {}
- type DFunInstType = Maybe Type
- pprInstance :: ClsInst -> SDoc
- pprInstanceHdr :: ClsInst -> SDoc
- pprInstances :: [ClsInst] -> SDoc
- instanceHead :: ClsInst -> ([TyVar], ThetaType, Class, [Type])
- mkLocalInstance :: DFunId -> OverlapFlag -> ClsInst
- mkImportedInstance :: Name -> [Maybe Name] -> DFunId -> OverlapFlag -> ClsInst
- instanceDFunId :: ClsInst -> DFunId
- setInstanceDFunId :: ClsInst -> DFunId -> ClsInst
- instanceRoughTcs :: ClsInst -> [Maybe Name]
- type InstEnv = UniqFM ClsInstEnv
- emptyInstEnv :: InstEnv
- extendInstEnv :: InstEnv -> ClsInst -> InstEnv
- overwriteInstEnv :: InstEnv -> ClsInst -> InstEnv
- extendInstEnvList :: InstEnv -> [ClsInst] -> InstEnv
- lookupUniqueInstEnv :: (InstEnv, InstEnv) -> Class -> [Type] -> Either MsgDoc (ClsInst, [Type])
- lookupInstEnv' :: InstEnv -> Class -> [Type] -> ([InstMatch], [ClsInst])
- lookupInstEnv :: (InstEnv, InstEnv) -> Class -> [Type] -> ClsInstLookupResult
- instEnvElts :: InstEnv -> [ClsInst]
- classInstances :: (InstEnv, InstEnv) -> Class -> [ClsInst]
- instanceBindFun :: TyVar -> BindFlag
- instanceCantMatch :: [Maybe Name] -> [Maybe Name] -> Bool
- roughMatchTcs :: [Type] -> [Maybe Name]
Documentation
data OverlapFlag
Constructors
NoOverlap | This instance must not overlap another |
Fields | |
OverlapOk | Silently ignore this instance if you find a more specific one that matches the constraint you are trying to resolve Example: constraint (Foo [Int]) instances (Foo [Int]) (Foo [a]) OverlapOk Since the second instance has the OverlapOk flag, the first instance will be chosen (otherwise its ambiguous which to choose) |
Fields | |
Incoherent | Like OverlapOk, but also ignore this instance if it doesn't match the constraint you are trying to resolve, but could match if the type variables in the constraint were instantiated Example: constraint (Foo [b])
instances (Foo [Int]) Incoherent
(Foo [a])
Without the Incoherent flag, we'd complain that
instantiating |
Fields |
type InstMatch = (ClsInst, [DFunInstType])
type ClsInstLookupResult = ([InstMatch], [ClsInst], Bool)
type DFunInstType = Maybe Type
pprInstance :: ClsInst -> SDoc
pprInstanceHdr :: ClsInst -> SDoc
pprInstances :: [ClsInst] -> SDoc
mkLocalInstance :: DFunId -> OverlapFlag -> ClsInst
mkImportedInstance :: Name -> [Maybe Name] -> DFunId -> OverlapFlag -> ClsInst
instanceDFunId :: ClsInst -> DFunId
setInstanceDFunId :: ClsInst -> DFunId -> ClsInst
instanceRoughTcs :: ClsInst -> [Maybe Name]
extendInstEnv :: InstEnv -> ClsInst -> InstEnv
overwriteInstEnv :: InstEnv -> ClsInst -> InstEnv
extendInstEnvList :: InstEnv -> [ClsInst] -> InstEnv
lookupUniqueInstEnv :: (InstEnv, InstEnv) -> Class -> [Type] -> Either MsgDoc (ClsInst, [Type])
Look up an instance in the given instance environment. The given class application must match exactly one instance and the match may not contain any flexi type variables. If the lookup is unsuccessful, yield 'Left errorMessage'.
lookupInstEnv :: (InstEnv, InstEnv) -> Class -> [Type] -> ClsInstLookupResult
instEnvElts :: InstEnv -> [ClsInst]
classInstances :: (InstEnv, InstEnv) -> Class -> [ClsInst]
instanceBindFun :: TyVar -> BindFlag
roughMatchTcs :: [Type] -> [Maybe Name]