+ HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (new_decl:decls, fvs1 `plusFV` fvs)
+
+ -- No declaration... (wired in thing, or deferred, or already slurped)
+ other -> returnRn (decls, fvs)
+
+
+-------------------------------------------------------
+rnIfaceDecls :: [RenamedHsDecl] -> FreeVars
+ -> [(Module, RdrNameHsDecl)]
+ -> RnM d ([RenamedHsDecl], FreeVars)
+rnIfaceDecls decls fvs [] = returnRn (decls, fvs)
+rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
+ rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds
+
+rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl)
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Deferred declarations}
+%* *
+%*********************************************************
+
+The idea of deferred declarations is this. Suppose we have a function
+ f :: T -> Int
+ data T = T1 A | T2 B
+ data A = A1 X | A2 Y
+ data B = B1 P | B2 Q
+Then we don't want to load T and all its constructors, and all
+the types those constructors refer to, and all the types *those*
+constructors refer to, and so on. That might mean loading many more
+interface files than is really necessary. So we 'defer' loading T.
+
+But f might be strict, and the calling convention for evaluating
+values of type T depends on how many constructors T has, so
+we do need to load T, but not the full details of the type T.
+So we load the full decl for T, but only skeleton decls for A and B:
+ f :: T -> Int
+ data T = {- 2 constructors -}
+
+Whether all this is worth it is moot.
+
+\begin{code}
+slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
+slurpDeferredDecls decls
+ = getDeferredDecls `thenRn` \ def_decls ->
+ rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) ->
+ ASSERT( isEmptyFVs fvs )
+ returnRn decls1
+
+stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ _ loc))
+ = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing NoDataPragmas loc))
+ -- Nuke the context and constructors
+ -- But retain the *number* of constructors!
+ -- Also the tvs will have kinds on them.