-[A BIT DATED [WDP]]
-
-The @Id@ datatype describes {\em values}. The basic things we want to
-know: (1)~a value's {\em type} (@idType@ is a very common
-operation in the compiler); and (2)~what ``flavour'' of value it might
-be---for example, it can be terribly useful to know that a value is a
-class method.
-
-\begin{description}
-%----------------------------------------------------------------------
-\item[@DataConId@:] For the data constructors declared by a @data@
-declaration. Their type is kept in {\em two} forms---as a regular
-@Type@ (in the usual place), and also in its constituent pieces (in
-the ``details''). We are frequently interested in those pieces.
-
-%----------------------------------------------------------------------
-\item[@TupleConId@:] This is just a special shorthand for @DataCons@ for
-the infinite family of tuples.
-
-%----------------------------------------------------------------------
-\item[@ImportedId@:] These are values defined outside this module.
-{\em Everything} we want to know about them must be stored here (or in
-their @IdInfo@).
-
-%----------------------------------------------------------------------
-\item[@PreludeId@:] ToDo
-
-%----------------------------------------------------------------------
-\item[@TopLevId@:] These are values defined at the top-level in this
-module; i.e., those which {\em might} be exported (hence, a
-@Name@). It does {\em not} include those which are moved to the
-top-level through program transformations.
-
-We also guarantee that @TopLevIds@ will {\em stay} at top-level.
-Theoretically, they could be floated inwards, but there's no known
-advantage in doing so. This way, we can keep them with the same
-@Unique@ throughout (no cloning), and, in general, we don't have to be
-so paranoid about them.
-
-In particular, we had the following problem generating an interface:
-We have to ``stitch together'' info (1)~from the typechecker-produced
-global-values list (GVE) and (2)~from the STG code [which @Ids@ have
-what arities]. If the @Uniques@ on the @TopLevIds@ can {\em change}
-between (1) and (2), you're sunk!
-
-%----------------------------------------------------------------------
-\item[@MethodSelId@:] A selector from a dictionary; it may select either
-a method or a dictionary for one of the class's superclasses.
-
-%----------------------------------------------------------------------
-\item[@DictFunId@:]
-
-@mkDictFunId [a,b..] theta C T@ is the function derived from the
-instance declaration
-
- instance theta => C (T a b ..) where
- ...
-
-It builds function @Id@ which maps dictionaries for theta,
-to a dictionary for C (T a b ..).
-
-*Note* that with the ``Mark Jones optimisation'', the theta may
-include dictionaries for the immediate superclasses of C at the type
-(T a b ..).
-
-%----------------------------------------------------------------------
-\item[@InstId@:]
-
-%----------------------------------------------------------------------
-\item[@SpecId@:]
-
-%----------------------------------------------------------------------
-\item[@WorkerId@:]
-
-%----------------------------------------------------------------------
-\item[@LocalId@:] A purely-local value, e.g., a function argument,
-something defined in a @where@ clauses, ... --- but which appears in
-the original program text.
-
-%----------------------------------------------------------------------
-\item[@SysLocalId@:] Same as a @LocalId@, except does {\em not} appear in
-the original program text; these are introduced by the compiler in
-doing its thing.
-
-%----------------------------------------------------------------------
-\item[@SpecPragmaId@:] Introduced by the compiler to record
-Specialisation pragmas. It is dead code which MUST NOT be removed
-before specialisation.
-\end{description}
-
-Further remarks:
-\begin{enumerate}
-%----------------------------------------------------------------------
-\item
-
-@DataCons@ @TupleCons@, @Importeds@, @TopLevIds@, @SuperDictSelIds@,
-@MethodSelIds@, @DictFunIds@, and @DefaultMethodIds@ have the following
-properties:
-\begin{itemize}
-\item
-They have no free type variables, so if you are making a
-type-variable substitution you don't need to look inside them.
-\item
-They are constants, so they are not free variables. (When the STG
-machine makes a closure, it puts all the free variables in the
-closure; the above are not required.)
-\end{itemize}
-Note that @InstIds@, @Locals@ and @SysLocals@ {\em may} have the above
-properties, but they may not.
-\end{enumerate}
-
-%************************************************************************
-%* *
-\subsection[Id-general-funs]{General @Id@-related functions}
-%* *
-%************************************************************************
-
-\begin{code}
-unsafeGenId2Id :: GenId ty -> Id
-unsafeGenId2Id (Id u ty d p i) = Id u (panic "unsafeGenId2Id:ty") d p i
-
-isDataCon id = is_data (unsafeGenId2Id id)
- where
- is_data (Id _ _ (DataConId _ _ _ _ _ _ _ _) _ _) = True
- is_data (Id _ _ (TupleConId _ _) _ _) = True
- is_data (Id _ _ (SpecId unspec _ _) _ _) = is_data unspec
- is_data other = False
-
-
-isTupleCon id = is_tuple (unsafeGenId2Id id)
- where
- is_tuple (Id _ _ (TupleConId _ _) _ _) = True
- is_tuple (Id _ _ (SpecId unspec _ _) _ _) = is_tuple unspec
- is_tuple other = False
-
-{-LATER:
-isSpecId_maybe (Id _ _ (SpecId unspec ty_maybes _) _ _)
- = ASSERT(not (maybeToBool (isSpecId_maybe unspec)))
- Just (unspec, ty_maybes)
-isSpecId_maybe other_id
- = Nothing
-
-isSpecPragmaId_maybe (Id _ _ (SpecPragmaId _ specid _) _ _)
- = Just specid
-isSpecPragmaId_maybe other_id
- = Nothing
--}
-\end{code}
-
-@toplevelishId@ tells whether an @Id@ {\em may} be defined in a
-nested @let(rec)@ (returns @False@), or whether it is {\em sure} to be
-defined at top level (returns @True@). This is used to decide whether
-the @Id@ is a candidate free variable. NB: you are only {\em sure}
-about something if it returns @True@!
-
-\begin{code}
-toplevelishId :: Id -> Bool
-idHasNoFreeTyVars :: Id -> Bool
-
-toplevelishId (Id _ _ details _ _)
- = chk details
- where
- chk (DataConId _ _ _ _ _ _ _ _) = True
- chk (TupleConId _ _) = True
- chk (RecordSelId _) = True
- chk (ImportedId _) = True
- chk (PreludeId _) = True
- chk (TopLevId _) = True -- NB: see notes
- chk (SuperDictSelId _ _) = True
- chk (MethodSelId _ _) = True
- chk (DefaultMethodId _ _ _) = True
- chk (DictFunId _ _ _ _) = True
- chk (ConstMethodId _ _ _ _ _) = True
- chk (SpecId unspec _ _) = toplevelishId unspec
- -- depends what the unspecialised thing is
- chk (WorkerId unwrkr) = toplevelishId unwrkr
- chk (InstId _ _) = False -- these are local
- chk (LocalId _ _) = False
- chk (SysLocalId _ _) = False
- chk (SpecPragmaId _ _ _) = False
-
-idHasNoFreeTyVars (Id _ _ details _ info)
- = chk details
- where
- chk (DataConId _ _ _ _ _ _ _ _) = True
- chk (TupleConId _ _) = True
- chk (RecordSelId _) = True
- chk (ImportedId _) = True
- chk (PreludeId _) = True
- chk (TopLevId _) = True
- chk (SuperDictSelId _ _) = True
- chk (MethodSelId _ _) = True
- chk (DefaultMethodId _ _ _) = True
- chk (DictFunId _ _ _ _) = True
- chk (ConstMethodId _ _ _ _ _) = True
- chk (WorkerId unwrkr) = idHasNoFreeTyVars unwrkr
- chk (InstId _ no_free_tvs) = no_free_tvs
- chk (SpecId _ _ no_free_tvs) = no_free_tvs
- chk (LocalId _ no_free_tvs) = no_free_tvs
- chk (SysLocalId _ no_free_tvs) = no_free_tvs
- chk (SpecPragmaId _ _ no_free_tvs) = no_free_tvs
-\end{code}