%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section{@Vars@: Variables}
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
+-- for details
+
module Var (
Var,
- varName, varUnique,
+ varName, varUnique, varType,
setVarName, setVarUnique,
-- TyVars
- TyVar, mkTyVar, mkTcTyVar,
+ TyVar, mkTyVar, mkTcTyVar, mkWildCoVar,
tyVarName, tyVarKind,
- setTyVarName, setTyVarUnique,
+ setTyVarName, setTyVarUnique, setTyVarKind,
tcTyVarDetails,
+ -- CoVars
+ CoVar, coVarName, setCoVarUnique, setCoVarName, mkCoVar, isCoVar,
+
-- Ids
Id, DictId,
idName, idType, idUnique, idInfo, modifyIdInfo, maybeModifyIdInfo,
setIdName, setIdUnique, setIdType, setIdInfo, lazySetIdInfo,
- setIdExported, setIdNotExported,
+ setIdExported, setIdNotExported,
globalIdDetails, globaliseId,
#include "HsVersions.h"
-import {-# SOURCE #-} TypeRep( Type )
+import {-# SOURCE #-} TypeRep( Type, Kind )
import {-# SOURCE #-} TcType( TcTyVarDetails, pprTcTyVarDetails )
-import {-# SOURCE #-} IdInfo( GlobalIdDetails, notGlobalId, IdInfo, seqIdInfo )
-
-import Name ( Name, NamedThing(..),
- setNameUnique, nameUnique
- )
-import Kind ( Kind )
-import Unique ( Unique, Uniquable(..), mkUniqueGrimily, getKey# )
+import {-# SOURCE #-} IdInfo( GlobalIdDetails, notGlobalId,
+ IdInfo, seqIdInfo )
+#ifdef DEBUG
+import {-# SOURCE #-} TypeRep( isCoercionKind )
+#endif
+
+import Name hiding (varName)
+import Unique
import FastTypes
-import Outputable
+import FastString
+import Outputable
\end{code}
realUnique :: FastInt, -- Key for fast comparison
-- Identical to the Unique in the name,
-- cached here for speed
- tyVarKind :: Kind }
+ varType :: Kind,
+ isCoercionVar :: Bool
+ }
| TcTyVar { -- Used only during type inference
+ -- Used for kind variables during
+ -- inference, as well
varName :: !Name,
realUnique :: FastInt,
- tyVarKind :: Kind,
+ varType :: Kind,
tcTyVarDetails :: TcTyVarDetails }
| GlobalId { -- Used for imported Ids, dict selectors etc
- varName :: !Name,
+ -- See Note [GlobalId/LocalId] below
+ varName :: !Name, -- Always an External or WiredIn Name
realUnique :: FastInt,
- idType :: Type,
- idInfo :: IdInfo,
+ varType :: Type,
+ idInfo_ :: IdInfo,
gblDetails :: GlobalIdDetails }
- | LocalId { -- Used for locally-defined Ids (see NOTE below)
+ | LocalId { -- Used for locally-defined Ids
+ -- See Note [GlobalId/LocalId] below
varName :: !Name,
realUnique :: FastInt,
- idType :: Type,
- idInfo :: IdInfo,
+ varType :: Type,
+ idInfo_ :: IdInfo,
lclDetails :: LocalIdDetails }
data LocalIdDetails
-- NotExported things may be discarded as dead code.
\end{code}
-LocalId and GlobalId
-~~~~~~~~~~~~~~~~~~~~
+Note [GlobalId/LocalId]
+~~~~~~~~~~~~~~~~~~~~~~~
A GlobalId is
* always a constant (top-level)
* imported, or data constructor, or primop, or record selector
* has a Unique that is globally unique across the whole
GHC invocation (a single invocation may compile multiple modules)
+ * never treated as a candidate by the free-variable finder;
+ it's a constant!
A LocalId is
* bound within an expression (lambda, case, local let(rec))
* or defined at top level in the module being compiled
+ * always treated as a candidate by the free-variable finder
After CoreTidy, top-level LocalIds are turned into GlobalIds
type TyVar = Var
tyVarName = varName
+tyVarKind = varType
setTyVarUnique = setVarUnique
setTyVarName = setVarName
+
+setTyVarKind :: TyVar -> Kind -> TyVar
+setTyVarKind tv k = tv {varType = k}
\end{code}
\begin{code}
mkTyVar :: Name -> Kind -> TyVar
-mkTyVar name kind = TyVar { varName = name
+mkTyVar name kind = ASSERT( not (isCoercionKind kind ) )
+ TyVar { varName = name
, realUnique = getKey# (nameUnique name)
- , tyVarKind = kind
+ , varType = kind
+ , isCoercionVar = False
}
mkTcTyVar :: Name -> Kind -> TcTyVarDetails -> TyVar
mkTcTyVar name kind details
- = TcTyVar { varName = name,
+ = -- TOM: no longer valid assertion?
+ -- ASSERT( not (isCoercionKind kind) )
+ TcTyVar { varName = name,
realUnique = getKey# (nameUnique name),
- tyVarKind = kind,
+ varType = kind,
tcTyVarDetails = details
}
\end{code}
+%************************************************************************
+%* *
+\subsection{Coercion variables}
+%* *
+%************************************************************************
+
+\begin{code}
+type CoVar = Var -- A coercion variable is simply a type
+ -- variable of kind (ty1 :=: ty2)
+coVarName = varName
+
+setCoVarUnique = setVarUnique
+setCoVarName = setVarName
+
+mkCoVar :: Name -> Kind -> CoVar
+mkCoVar name kind = ASSERT( isCoercionKind kind )
+ TyVar { varName = name
+ , realUnique = getKey# (nameUnique name)
+ , varType = kind
+ , isCoercionVar = True
+ }
+
+mkWildCoVar :: Kind -> TyVar
+-- A type variable that is never referred to,
+-- so its unique doesn't matter
+mkWildCoVar kind
+ = ASSERT( isCoercionKind kind )
+ TyVar { varName = mkSysTvName wild_uniq FSLIT("co_wild"),
+ realUnique = _ILIT(1),
+ varType = kind,
+ isCoercionVar = True }
+ where
+ wild_uniq = mkBuiltinUnique 1
+\end{code}
%************************************************************************
%* *
\begin{code}
idName = varName
idUnique = varUnique
+idType = varType
setIdUnique :: Id -> Unique -> Id
setIdUnique = setVarUnique
setIdName = setVarName
setIdType :: Id -> Type -> Id
-setIdType id ty = id {idType = ty}
+setIdType id ty = id {varType = ty}
setIdExported :: Id -> Id
-- Can be called on GlobalIds, such as data cons and class ops,
-- If it's a local, make it global
globaliseId details id = GlobalId { varName = varName id,
realUnique = realUnique id,
- idType = idType id,
- idInfo = idInfo id,
+ varType = varType id,
+ idInfo_ = idInfo id,
gblDetails = details }
+idInfo :: Id -> IdInfo
+idInfo (GlobalId {idInfo_ = info}) = info
+idInfo (LocalId {idInfo_ = info}) = info
+idInfo other_var = pprPanic "idInfo" (ppr other_var)
+
lazySetIdInfo :: Id -> IdInfo -> Id
-lazySetIdInfo id info = id {idInfo = info}
+lazySetIdInfo id info = id {idInfo_ = info}
setIdInfo :: Id -> IdInfo -> Id
-setIdInfo id info = seqIdInfo info `seq` id {idInfo = info}
+setIdInfo id info = seqIdInfo info `seq` id {idInfo_ = info}
-- Try to avoid spack leaks by seq'ing
modifyIdInfo :: (IdInfo -> IdInfo) -> Id -> Id
modifyIdInfo fn id
- = seqIdInfo new_info `seq` id {idInfo = new_info}
+ = seqIdInfo new_info `seq` id {idInfo_ = new_info}
where
new_info = fn (idInfo id)
-- maybeModifyIdInfo tries to avoid unnecesary thrashing
-maybeModifyIdInfo :: (IdInfo -> Maybe IdInfo) -> Id -> Id
-maybeModifyIdInfo fn id
- = case fn (idInfo id) of
- Nothing -> id
- Just new_info -> id {idInfo = new_info}
+maybeModifyIdInfo :: Maybe IdInfo -> Id -> Id
+maybeModifyIdInfo (Just new_info) id = id {idInfo_ = new_info}
+maybeModifyIdInfo Nothing id = id
\end{code}
%************************************************************************
mkGlobalId details name ty info
= GlobalId { varName = name,
realUnique = getKey# (nameUnique name), -- Cache the unique
- idType = ty,
+ varType = ty,
gblDetails = details,
- idInfo = info }
+ idInfo_ = info }
mk_local_id :: Name -> Type -> LocalIdDetails -> IdInfo -> Id
mk_local_id name ty details info
= LocalId { varName = name,
realUnique = getKey# (nameUnique name), -- Cache the unique
- idType = ty,
+ varType = ty,
lclDetails = details,
- idInfo = info }
+ idInfo_ = info }
mkLocalId :: Name -> Type -> IdInfo -> Id
mkLocalId name ty info = mk_local_id name ty NotExported info
isLocalId (LocalId {}) = True
isLocalId other = False
+isCoVar (v@(TyVar {})) = isCoercionVar v
+isCoVar other = False
+
-- isLocalVar returns True for type variables as well as local Ids
-- These are the variables that we need to pay attention to when finding free
-- variables, or doing dependency analysis.
projects / ghc-hetmet.git / blobdiff