+paMethod :: (Builtins -> Var) -> Type -> VM CoreExpr
+paMethod method ty
+ = do
+ fn <- builtin method
+ dict <- paDictOfType ty
+ return $ mkApps (Var fn) [Type ty, dict]
+
+lengthPA :: CoreExpr -> VM CoreExpr
+lengthPA x = liftM (`App` x) (paMethod lengthPAVar ty)
+ where
+ ty = splitPArrayTy (exprType x)
+
+replicatePA :: CoreExpr -> CoreExpr -> VM CoreExpr
+replicatePA len x = liftM (`mkApps` [len,x])
+ (paMethod replicatePAVar (exprType x))
+
+emptyPA :: Type -> VM CoreExpr
+emptyPA = paMethod emptyPAVar
+
+abstractOverTyVars :: [TyVar] -> ((CoreExpr -> CoreExpr) -> VM a) -> VM a
+abstractOverTyVars tvs p
+ = do
+ mdicts <- mapM mk_dict_var tvs
+ zipWithM_ (\tv -> maybe (defLocalTyVar tv) (defLocalTyVarWithPA tv . Var)) tvs mdicts
+ p (mk_lams mdicts)
+ where
+ mk_dict_var tv = do
+ r <- paDictArgType tv
+ case r of
+ Just ty -> liftM Just (newLocalVar FSLIT("dPA") ty)
+ Nothing -> return Nothing
+
+ mk_lams mdicts = mkLams (tvs ++ [dict | Just dict <- mdicts])
+
+applyToTypes :: CoreExpr -> [Type] -> VM CoreExpr
+applyToTypes expr tys
+ = do
+ dicts <- mapM paDictOfType tys
+ return $ expr `mkTyApps` tys `mkApps` dicts
+