tyVarName, tyVarKind,
setTyVarName, setTyVarUnique,
mkTyVar, mkSysTyVar,
- newMutTyVar, newSigTyVar,
- readMutTyVar, writeMutTyVar, makeTyVarImmutable,
+ newMutTyVar, readMutTyVar, writeMutTyVar, makeTyVarImmutable,
-- Ids
Id, DictId,
mkLocalId, mkGlobalId, mkSpecPragmaId,
- isTyVar, isMutTyVar, isSigTyVar,
+ isTyVar, isMutTyVar, mutTyVarDetails,
isId, isLocalVar, isLocalId,
isGlobalId, isExportedId, isSpecPragmaId,
mustHaveLocalBinding
#include "HsVersions.h"
import {-# SOURCE #-} TypeRep( Type, Kind )
+import {-# SOURCE #-} TcType( TyVarDetails )
import {-# SOURCE #-} IdInfo( GlobalIdDetails, notGlobalId,
IdInfo, seqIdInfo )
\begin{code}
data Var
= Var {
- varName :: Name,
+ varName :: !Name,
realUnique :: FastInt, -- Key for fast comparison
-- Identical to the Unique in the name,
-- cached here for speed
| TyVar
| MutTyVar (IORef (Maybe Type)) -- Used during unification;
- Bool -- True <=> this is a type signature variable, which
- -- should not be unified with a non-tyvar type
+ TyVarDetails
-- For a long time I tried to keep mutable Vars statically type-distinct
-- from immutable Vars, but I've finally given up. It's just too painful.
where
name = mkSysLocalName uniq SLIT("t")
-newMutTyVar :: Name -> Kind -> IO TyVar
-newMutTyVar name kind = newTyVar name kind False
-
-newSigTyVar :: Name -> Kind -> IO TyVar
--- Type variables from type signatures are still mutable, because
--- they may get unified with type variables from other signatures
--- But they do contain a flag to distinguish them, so we can tell if
--- we unify them with a non-type-variable.
-newSigTyVar name kind = newTyVar name kind True
-
-newTyVar name kind is_sig
- = do loc <- newIORef Nothing
- return (Var { varName = name
- , realUnique = getKey (nameUnique name)
- , varType = kind
- , varDetails = MutTyVar loc is_sig
- , varInfo = pprPanic "newMutTyVar" (ppr name)
- })
+newMutTyVar :: Name -> Kind -> TyVarDetails -> IO TyVar
+newMutTyVar name kind details
+ = do loc <- newIORef Nothing
+ return (Var { varName = name
+ , realUnique = getKey (nameUnique name)
+ , varType = kind
+ , varDetails = MutTyVar loc details
+ , varInfo = pprPanic "newMutTyVar" (ppr name)
+ })
readMutTyVar :: TyVar -> IO (Maybe Type)
readMutTyVar (Var {varDetails = MutTyVar loc _}) = readIORef loc
makeTyVarImmutable :: TyVar -> TyVar
makeTyVarImmutable tyvar = tyvar { varDetails = TyVar}
+
+mutTyVarDetails :: TyVar -> TyVarDetails
+mutTyVarDetails (Var {varDetails = MutTyVar _ details}) = details
\end{code}
\end{code}
\begin{code}
-isTyVar, isMutTyVar, isSigTyVar :: Var -> Bool
+isTyVar, isMutTyVar :: Var -> Bool
isId, isLocalVar, isLocalId :: Var -> Bool
isGlobalId, isExportedId, isSpecPragmaId :: Var -> Bool
mustHaveLocalBinding :: Var -> Bool
isMutTyVar (Var {varDetails = MutTyVar _ _}) = True
isMutTyVar other = False
-isSigTyVar (Var {varDetails = MutTyVar _ is_sig}) = is_sig
-isSigTyVar other = False
isId var = case varDetails var of
LocalId _ -> True