--
-- * 'Id.Id': see "Id#name_types"
--
--- * 'Var.Var' is a synonym for the 'Id.Id' type but it may additionally potentially contain type variables,
--- which have a 'TypeRep.Kind' rather than a 'TypeRep.Type' and only contain some extra details during typechecking.
+-- * 'Var.Var' is a synonym for the 'Id.Id' type but it may additionally
+-- potentially contain type variables, which have a 'TypeRep.Kind'
+-- rather than a 'TypeRep.Type' and only contain some extra
+-- details during typechecking.
+--
-- These 'Var.Var' names may either be global or local, see "Var#globalvslocal"
--
-- #globalvslocal#
--- Global 'Id's and 'Var's are those that are imported or correspond to a data constructor, primitive operation, or record selectors.
--- Local 'Id's and 'Var's are those bound within an expression (e.g. by a lambda) or at the top level of the module being compiled.
-module Var (
- -- * The main data type
- Var,
+-- Global 'Id's and 'Var's are those that are imported or correspond
+-- to a data constructor, primitive operation, or record selectors.
+-- Local 'Id's and 'Var's are those bound within an expression
+-- (e.g. by a lambda) or at the top level of the module being compiled.
- -- ** Constructing 'Var's
- mkLocalIdVar, mkExportedLocalIdVar, mkGlobalIdVar,
+module Var (
+ -- * The main data type and synonyms
+ Var, TyVar, CoVar, TyCoVar, Id, DictId, DFunId, EvVar, EvId, IpId,
-- ** Taking 'Var's apart
- varName, varUnique, varType, varIdInfo, globalIdVarDetails,
+ varName, varUnique, varType,
-- ** Modifying 'Var's
setVarName, setVarUnique, setVarType,
- setIdVarExported, setIdVarNotExported,
- globaliseIdVar, lazySetVarIdInfo,
+
+ -- ** Constructing, taking apart, modifying 'Id's
+ mkGlobalVar, mkLocalVar, mkExportedLocalVar, mkCoVar,
+ idInfo, idDetails,
+ lazySetIdInfo, setIdDetails, globaliseId,
+ setIdExported, setIdNotExported,
-- ** Predicates
- isCoVar, isIdVar, isTyVar, isTcTyVar,
- isLocalVar, isLocalIdVar,
- isGlobalIdVar, isExportedIdVar,
+ isId, isTyVar, isTcTyVar,
+ isLocalVar, isLocalId,
+ isGlobalId, isExportedId,
mustHaveLocalBinding,
- -- * Type variable data type
- TyVar,
-
-- ** Constructing 'TyVar's
- mkTyVar, mkTcTyVar, mkWildCoVar,
+ mkTyVar, mkTcTyVar,
-- ** Taking 'TyVar's apart
- tyVarName, tyVarKind, tcTyVarDetails,
+ tyVarName, tyVarKind, tcTyVarDetails, setTcTyVarDetails,
-- ** Modifying 'TyVar's
- setTyVarName, setTyVarUnique, setTyVarKind,
-
- -- * Coercion variable data type
- CoVar,
+ setTyVarName, setTyVarUnique, setTyVarKind
- -- ** Constructing 'CoVar's
- mkCoVar,
-
- -- ** Taking 'CoVar's apart
- coVarName,
-
- -- ** Modifying 'CoVar's
- setCoVarUnique, setCoVarName,
-
- -- * 'Var' type synonyms
- Id, DictId
) where
#include "HsVersions.h"
+#include "Typeable.h"
import {-# SOURCE #-} TypeRep( Type, Kind )
import {-# SOURCE #-} TcType( TcTyVarDetails, pprTcTyVarDetails )
-import {-# SOURCE #-} IdInfo( GlobalIdDetails, notGlobalId,
- IdInfo )
-import {-# SOURCE #-} TypeRep( isCoercionKind )
+import {-# SOURCE #-} IdInfo( IdDetails, IdInfo, coVarDetails, vanillaIdInfo, pprIdDetails )
import Name hiding (varName)
import Unique
+import Util
import FastTypes
import FastString
import Outputable
+
+import Data.Data
\end{code}
%************************************************************************
%* *
+ Synonyms
+%* *
+%************************************************************************
+-- These synonyms are here and not in Id because otherwise we need a very
+-- large number of SOURCE imports of Id.hs :-(
+
+\begin{code}
+type EvVar = Var -- An evidence variable: dictionary or equality constraint
+ -- Could be an DictId or a CoVar
+
+type Id = Var -- A term-level identifier
+type DFunId = Id -- A dictionary function
+type EvId = Id -- Term-level evidence: DictId or IpId
+type DictId = EvId -- A dictionary variable
+type IpId = EvId -- A term-level implicit parameter
+
+type TyVar = Var
+type CoVar = Id -- A coercion variable is simply an Id
+ -- variable of kind @ty1 ~ ty2@. Hence its
+ -- 'varType' is always @PredTy (EqPred t1 t2)@
+type TyCoVar = TyVar -- Something that is a type OR coercion variable.
+\end{code}
+
+%************************************************************************
+%* *
\subsection{The main data type declarations}
%* *
%************************************************************************
realUnique :: FastInt, -- Key for fast comparison
-- Identical to the Unique in the name,
-- cached here for speed
- varType :: Kind, -- ^ The type or kind of the 'Var' in question
- isCoercionVar :: Bool
+ varType :: Kind -- ^ The type or kind of the 'Var' in question
}
| TcTyVar { -- Used only during type inference
varName :: !Name,
realUnique :: FastInt,
varType :: Kind,
- tcTyVarDetails :: TcTyVarDetails }
+ tc_tv_details :: TcTyVarDetails }
- | GlobalId { -- Used for imported Ids, dict selectors etc
- -- See Note [GlobalId/LocalId] below
- varName :: !Name, -- Always an External or WiredIn Name
- realUnique :: FastInt,
- varType :: Type,
- idInfo_ :: IdInfo,
- gblDetails :: GlobalIdDetails }
-
- | LocalId { -- Used for locally-defined Ids
- -- See Note [GlobalId/LocalId] below
+ | Id {
varName :: !Name,
realUnique :: FastInt,
varType :: Type,
- idInfo_ :: IdInfo,
- lclDetails :: LocalIdDetails }
+ idScope :: IdScope,
+ id_details :: IdDetails, -- Stable, doesn't change
+ id_info :: IdInfo } -- Unstable, updated by simplifier
+ deriving Typeable
+
+data IdScope -- See Note [GlobalId/LocalId]
+ = GlobalId
+ | LocalId ExportFlag
-data LocalIdDetails
+data ExportFlag
= NotExported -- ^ Not exported: may be discarded as dead code.
| Exported -- ^ Exported: kept alive
\end{code}
\begin{code}
instance Outputable Var where
- ppr var = ppr (varName var) <+> ifPprDebug (brackets extra)
- where
- extra = case var of
- GlobalId {} -> ptext (sLit "gid")
- LocalId {} -> ptext (sLit "lid")
- TyVar {} -> ptext (sLit "tv")
- TcTyVar {tcTyVarDetails = details} -> pprTcTyVarDetails details
+ ppr var = ppr (varName var) <+> ifPprDebug (brackets (ppr_debug var))
+
+ppr_debug :: Var -> SDoc
+ppr_debug (TyVar {}) = ptext (sLit "tv")
+ppr_debug (TcTyVar {tc_tv_details = d}) = pprTcTyVarDetails d
+ppr_debug (Id { idScope = s, id_details = d }) = ppr_id_scope s <> pprIdDetails d
+
+ppr_id_scope :: IdScope -> SDoc
+ppr_id_scope GlobalId = ptext (sLit "gid")
+ppr_id_scope (LocalId Exported) = ptext (sLit "lidx")
+ppr_id_scope (LocalId NotExported) = ptext (sLit "lid")
instance Show Var where
showsPrec p var = showsPrecSDoc p (ppr var)
a >= b = realUnique a >=# realUnique b
a > b = realUnique a ># realUnique b
a `compare` b = varUnique a `compare` varUnique b
+
+instance Data Var where
+ -- don't traverse?
+ toConstr _ = abstractConstr "Var"
+ gunfold _ _ = error "gunfold"
+ dataTypeOf _ = mkNoRepType "Var"
\end{code}
setVarType :: Id -> Type -> Id
setVarType id ty = id { varType = ty }
-
-setIdVarExported :: Var -> Var
--- ^ Exports the given local 'Id'. Can also be called on global 'Id's, such as data constructors
--- and class operations, which are born as global 'Id's and automatically exported
-setIdVarExported id@(LocalId {}) = id { lclDetails = Exported }
-setIdVarExported other_id = ASSERT( isIdVar other_id ) other_id
-
-setIdVarNotExported :: Id -> Id
--- ^ We can only do this to LocalIds
-setIdVarNotExported id = ASSERT( isLocalIdVar id ) id { lclDetails = NotExported }
-
-globaliseIdVar :: GlobalIdDetails -> Var -> Var
--- ^ If it's a local, make it global
-globaliseIdVar details id = GlobalId { varName = varName id,
- realUnique = realUnique id,
- varType = varType id,
- idInfo_ = varIdInfo id,
- gblDetails = details }
-
--- | Extract 'Id' information from the 'Var' if it represents a global or local 'Id', otherwise panic
-varIdInfo :: Var -> IdInfo
-varIdInfo (GlobalId {idInfo_ = info}) = info
-varIdInfo (LocalId {idInfo_ = info}) = info
-varIdInfo other_var = pprPanic "idInfo" (ppr other_var)
-
-lazySetVarIdInfo :: Var -> IdInfo -> Var
-lazySetVarIdInfo id info = id { idInfo_ = info }
\end{code}
%************************************************************************
\begin{code}
-type TyVar = Var
-
tyVarName :: TyVar -> Name
tyVarName = varName
\begin{code}
mkTyVar :: Name -> Kind -> TyVar
-mkTyVar name kind = ASSERT( not (isCoercionKind kind ) )
- TyVar { varName = name
+mkTyVar name kind = TyVar { varName = name
, realUnique = getKeyFastInt (nameUnique name)
, varType = kind
- , isCoercionVar = False
}
mkTcTyVar :: Name -> Kind -> TcTyVarDetails -> TyVar
mkTcTyVar name kind details
- = -- TOM: no longer valid assertion?
- -- ASSERT( not (isCoercionKind kind) )
+ = -- NB: 'kind' may be a coercion kind; cf, 'TcMType.newMetaCoVar'
TcTyVar { varName = name,
realUnique = getKeyFastInt (nameUnique name),
varType = kind,
- tcTyVarDetails = details
+ tc_tv_details = details
}
+
+tcTyVarDetails :: TyVar -> TcTyVarDetails
+tcTyVarDetails (TcTyVar { tc_tv_details = details }) = details
+tcTyVarDetails var = pprPanic "tcTyVarDetails" (ppr var)
+
+setTcTyVarDetails :: TyVar -> TcTyVarDetails -> TyVar
+setTcTyVarDetails tv details = tv { tc_tv_details = details }
\end{code}
%************************************************************************
%* *
-\subsection{Coercion variables}
+\subsection{Ids}
%* *
%************************************************************************
\begin{code}
-type CoVar = Var -- ^ A coercion variable is simply a type
- -- variable of kind @ty1 :=: ty2@. Hence its
- -- 'varType' is always @PredTy (EqPred t1 t2)@
-
-coVarName :: CoVar -> Name
-coVarName = varName
-
-setCoVarUnique :: CoVar -> Unique -> CoVar
-setCoVarUnique = setVarUnique
+idInfo :: Id -> IdInfo
+idInfo (Id { id_info = info }) = info
+idInfo other = pprPanic "idInfo" (ppr other)
-setCoVarName :: CoVar -> Name -> CoVar
-setCoVarName = setVarName
+idDetails :: Id -> IdDetails
+idDetails (Id { id_details = details }) = details
+idDetails other = pprPanic "idDetails" (ppr other)
-mkCoVar :: Name -> Kind -> CoVar
-mkCoVar name kind = ASSERT( isCoercionKind kind )
- TyVar { varName = name
- , realUnique = getKeyFastInt (nameUnique name)
- , varType = kind
- , isCoercionVar = True
- }
+-- The next three have a 'Var' suffix even though they always build
+-- Ids, becuase Id.lhs uses 'mkGlobalId' etc with different types
+mkGlobalVar :: IdDetails -> Name -> Type -> IdInfo -> Id
+mkGlobalVar details name ty info
+ = mk_id name ty GlobalId details info
-mkWildCoVar :: Kind -> TyVar
--- ^ Create 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
+mkLocalVar :: IdDetails -> Name -> Type -> IdInfo -> Id
+mkLocalVar details name ty info
+ = mk_id name ty (LocalId NotExported) details info
-\end{code}
+mkCoVar :: Name -> Type -> CoVar
+-- Coercion variables have no IdInfo
+mkCoVar name ty = mk_id name ty (LocalId NotExported) coVarDetails vanillaIdInfo
-%************************************************************************
-%* *
-\subsection{Ids}
-%* *
-%************************************************************************
-
-\begin{code}
+-- | Exported 'Var's will not be removed as dead code
+mkExportedLocalVar :: IdDetails -> Name -> Type -> IdInfo -> Id
+mkExportedLocalVar details name ty info
+ = mk_id name ty (LocalId Exported) details info
+
+mk_id :: Name -> Type -> IdScope -> IdDetails -> IdInfo -> Id
+mk_id name ty scope details info
+ = Id { varName = name,
+ realUnique = getKeyFastInt (nameUnique name),
+ varType = ty,
+ idScope = scope,
+ id_details = details,
+ id_info = info }
+
+-------------------
+lazySetIdInfo :: Id -> IdInfo -> Var
+lazySetIdInfo id info = id { id_info = info }
+
+setIdDetails :: Id -> IdDetails -> Id
+setIdDetails id details = id { id_details = details }
+
+globaliseId :: Id -> Id
+-- ^ If it's a local, make it global
+globaliseId id = id { idScope = GlobalId }
--- These synonyms are here and not in Id because otherwise we need a very
--- large number of SOURCE imports of Id.hs :-(
-type Id = Var
-type DictId = Var
+setIdExported :: Id -> Id
+-- ^ Exports the given local 'Id'. Can also be called on global 'Id's, such as data constructors
+-- and class operations, which are born as global 'Id's and automatically exported
+setIdExported id@(Id { idScope = LocalId {} }) = id { idScope = LocalId Exported }
+setIdExported id@(Id { idScope = GlobalId }) = id
+setIdExported tv = pprPanic "setIdExported" (ppr tv)
+setIdNotExported :: Id -> Id
+-- ^ We can only do this to LocalIds
+setIdNotExported id = ASSERT( isLocalId id )
+ id { idScope = LocalId NotExported }
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
--- | For an explanation of global vs. local 'Var's, see "Var#globalvslocal"
-mkGlobalIdVar :: GlobalIdDetails -> Name -> Type -> IdInfo -> Var
-mkGlobalIdVar details name ty info
- = GlobalId { varName = name,
- realUnique = getKeyFastInt (nameUnique name), -- Cache the unique
- varType = ty,
- gblDetails = details,
- idInfo_ = info }
-
-mkLocalIdVar' :: Name -> Type -> LocalIdDetails -> IdInfo -> Var
-mkLocalIdVar' name ty details info
- = LocalId { varName = name,
- realUnique = getKeyFastInt (nameUnique name), -- Cache the unique
- varType = ty,
- lclDetails = details,
- idInfo_ = info }
-
--- | For an explanation of global vs. local 'Var's, see "Var#globalvslocal"
-mkLocalIdVar :: Name -> Type -> IdInfo -> Var
-mkLocalIdVar name ty info = mkLocalIdVar' name ty NotExported info
-
--- | Exported 'Var's will not be removed as dead code
-mkExportedLocalIdVar :: Name -> Type -> IdInfo -> Var
-mkExportedLocalIdVar name ty info = mkLocalIdVar' name ty Exported info
-\end{code}
-
-\begin{code}
-isTyVar :: Var -> Bool
+isTyVar :: Var -> Bool -- True of both type variables only
isTyVar (TyVar {}) = True
isTyVar (TcTyVar {}) = True
isTyVar _ = False
isTcTyVar (TcTyVar {}) = True
isTcTyVar _ = False
-isIdVar :: Var -> Bool
-isIdVar (LocalId {}) = True
-isIdVar (GlobalId {}) = True
-isIdVar _ = False
+isId :: Var -> Bool
+isId (Id {}) = True
+isId _ = False
-isLocalIdVar :: Var -> Bool
-isLocalIdVar (LocalId {}) = True
-isLocalIdVar _ = False
-
-isCoVar :: Var -> Bool
-isCoVar (v@(TyVar {})) = isCoercionVar v
-isCoVar _ = False
+isLocalId :: Var -> Bool
+isLocalId (Id { idScope = LocalId _ }) = True
+isLocalId _ = False
-- | 'isLocalVar' returns @True@ for type variables as well as local 'Id's
-- These are the variables that we need to pay attention to when finding free
-- variables, or doing dependency analysis.
isLocalVar :: Var -> Bool
-isLocalVar (GlobalId {}) = False
-isLocalVar _ = True
+isLocalVar v = not (isGlobalId v)
+
+isGlobalId :: Var -> Bool
+isGlobalId (Id { idScope = GlobalId }) = True
+isGlobalId _ = False
-- | 'mustHaveLocalBinding' returns @True@ of 'Id's and 'TyVar's
-- that must have a binding in this module. The converse
mustHaveLocalBinding :: Var -> Bool
mustHaveLocalBinding var = isLocalVar var
-isGlobalIdVar :: Var -> Bool
-isGlobalIdVar (GlobalId {}) = True
-isGlobalIdVar _ = False
-
-- | 'isExportedIdVar' means \"don't throw this away\"
-isExportedIdVar :: Var -> Bool
-isExportedIdVar (GlobalId {}) = True
-isExportedIdVar (LocalId {lclDetails = details})
- = case details of
- Exported -> True
- _ -> False
-isExportedIdVar _ = False
-\end{code}
-
-\begin{code}
-globalIdVarDetails :: Var -> GlobalIdDetails
--- ^ Find the global 'Id' information if the 'Var' is a global 'Id', otherwise returns 'notGlobalId'
-globalIdVarDetails (GlobalId {gblDetails = details}) = details
-globalIdVarDetails _ = notGlobalId
+isExportedId :: Var -> Bool
+isExportedId (Id { idScope = GlobalId }) = True
+isExportedId (Id { idScope = LocalId Exported}) = True
+isExportedId _ = False
\end{code}
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