Var
Contents
Description
GHC uses several kinds of name internally:
-
OccName.OccName
: see OccName -
RdrName.RdrName
: see RdrName -
Name
: see Name -
Id.Id
: see Id -
Var
is a synonym for theId.Id
type but it may additionally potentially contain type variables, which have aKind
rather than aType
and only contain some extra details during typechecking. TheseVar
names may either be global or local, see 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.
- data Var
- type TyVar = Var
- type CoVar = TyVar
- type Id = Var
- type DictId = EvId
- type DFunId = Id
- type EvVar = Var
- type EvId = Id
- type IpId = EvId
- varName :: Var -> Name
- varUnique :: Var -> Unique
- varType :: Var -> Kind
- setVarName :: Var -> Name -> Var
- setVarUnique :: Var -> Unique -> Var
- setVarType :: Id -> Type -> Id
- mkGlobalVar :: IdDetails -> Name -> Type -> IdInfo -> Id
- mkLocalVar :: IdDetails -> Name -> Type -> IdInfo -> Id
- mkExportedLocalVar :: IdDetails -> Name -> Type -> IdInfo -> Id
- idInfo :: Id -> IdInfo
- idDetails :: Id -> IdDetails
- lazySetIdInfo :: Id -> IdInfo -> Var
- setIdDetails :: Id -> IdDetails -> Id
- globaliseId :: Id -> Id
- setIdExported :: Id -> Id
- setIdNotExported :: Id -> Id
- isCoVar :: Var -> Bool
- isId :: Var -> Bool
- isTyCoVar :: Var -> Bool
- isTyVar :: Var -> Bool
- isTcTyVar :: Var -> Bool
- isLocalVar :: Var -> Bool
- isLocalId :: Var -> Bool
- isGlobalId :: Var -> Bool
- isExportedId :: Var -> Bool
- mustHaveLocalBinding :: Var -> Bool
- mkTyVar :: Name -> Kind -> TyVar
- mkTcTyVar :: Name -> Kind -> TcTyVarDetails -> TyVar
- mkWildCoVar :: Kind -> TyVar
- tyVarName :: TyVar -> Name
- tyVarKind :: TyVar -> Kind
- tcTyVarDetails :: TyVar -> TcTyVarDetails
- setTcTyVarDetails :: TyVar -> TcTyVarDetails -> TyVar
- setTyVarName :: TyVar -> Name -> TyVar
- setTyVarUnique :: TyVar -> Unique -> TyVar
- setTyVarKind :: TyVar -> Kind -> TyVar
- mkCoVar :: Name -> Kind -> CoVar
- coVarName :: CoVar -> Name
- setCoVarUnique :: CoVar -> Unique -> CoVar
- setCoVarName :: CoVar -> Name -> CoVar
The main data type and synonyms
data Var
Taking Var
s apart
Modifying Var
s
setVarName :: Var -> Name -> Var
setVarUnique :: Var -> Unique -> Var
setVarType :: Id -> Type -> Id
Constructing, taking apart, modifying Id
s
mkExportedLocalVar :: IdDetails -> Name -> Type -> IdInfo -> Id
Exported Var
s will not be removed as dead code
lazySetIdInfo :: Id -> IdInfo -> Var
setIdDetails :: Id -> IdDetails -> Id
globaliseId :: Id -> Id
If it's a local, make it global
setIdExported :: Id -> Id
setIdNotExported :: Id -> Id
We can only do this to LocalIds
Predicates
isLocalVar :: Var -> Bool
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.
isGlobalId :: Var -> Bool
isExportedId :: Var -> Bool
isExportedIdVar
means "don't throw this away"
mustHaveLocalBinding :: Var -> Bool
mustHaveLocalBinding
returns True
of Id
s and TyVar
s
that must have a binding in this module. The converse
is not quite right: there are some global Id
s that must have
bindings, such as record selectors. But that doesn't matter,
because it's only used for assertions
Constructing TyVar
s
mkTcTyVar :: Name -> Kind -> TcTyVarDetails -> TyVar
mkWildCoVar :: Kind -> TyVar
Create a type variable that is never referred to, so its unique doesn't matter
Taking TyVar
s apart
setTcTyVarDetails :: TyVar -> TcTyVarDetails -> TyVar
Modifying TyVar
s
setTyVarName :: TyVar -> Name -> TyVar
setTyVarUnique :: TyVar -> Unique -> TyVar
setTyVarKind :: TyVar -> Kind -> TyVar
Constructing CoVar
s
Taking CoVar
s apart
Modifying CoVar
s
setCoVarUnique :: CoVar -> Unique -> CoVar
setCoVarName :: CoVar -> Name -> CoVar