+getLiterals lit@(CoreSyn.Lit _) = [lit]
+
+reduceCoreListToHsList ::
+ [HscTypes.CoreModule] -- ^ The modules where parts of the list are hidden
+ -> CoreSyn.CoreExpr -- ^ The refence to atleast one of the nodes
+ -> TranslatorSession [CoreSyn.CoreExpr]
+reduceCoreListToHsList cores app@(CoreSyn.App _ _) = do {
+ ; let { (fun, args) = CoreSyn.collectArgs app
+ ; len = length args
+ } ;
+ ; case len of
+ 3 -> do {
+ ; let topelem = args!!1
+ ; case (args!!2) of
+ (varz@(CoreSyn.Var id)) -> do {
+ ; binds <- mapM (findExpr (isVarName id)) cores
+ ; otherelems <- reduceCoreListToHsList cores (head (Maybe.catMaybes binds))
+ ; return (topelem:otherelems)
+ }
+ (appz@(CoreSyn.App _ _)) -> do {
+ ; otherelems <- reduceCoreListToHsList cores appz
+ ; return (topelem:otherelems)
+ }
+ otherwise -> return [topelem]
+ }
+ otherwise -> return []
+ }
+ where
+ isVarName :: Monad m => Var.Var -> Var.Var -> m Bool
+ isVarName lookfor bind = return $ (Var.varName lookfor) == (Var.varName bind)
+
+reduceCoreListToHsList _ _ = return []
+
+-- Is the given var the State data constructor?
+isStateCon :: Var.Var -> Bool
+isStateCon var = do
+ -- See if it is a DataConWrapId (not DataConWorkId, since State is a
+ -- newtype).
+ case Id.idDetails var of
+ IdInfo.DataConWrapId dc ->
+ -- See if the datacon is the State datacon from the State type.
+ let tycon = DataCon.dataConTyCon dc
+ tyname = Name.getOccString tycon
+ dcname = Name.getOccString dc
+ in case (tyname, dcname) of
+ ("State", "State") -> True
+ _ -> False
+ _ -> False
+
+-- | Is the given type a State type?
+isStateType :: Type.Type -> Bool
+-- Resolve any type synonyms remaining
+isStateType ty | Just ty' <- Type.tcView ty = isStateType ty'
+isStateType ty = Maybe.isJust $ do
+ -- Split the type. Don't use normal splitAppTy, since that looks through
+ -- newtypes, and we want to see the State newtype.
+ (typef, _) <- Type.repSplitAppTy_maybe ty
+ -- See if the applied type is a type constructor
+ (tycon, _) <- Type.splitTyConApp_maybe typef
+ if TyCon.isNewTyCon tycon && Name.getOccString tycon == "State"
+ then
+ Just ()
+ else
+ Nothing
+
+-- | Does the given TypedThing have a State type?
+hasStateType :: (TypedThing t) => t -> Bool
+hasStateType expr = case getType expr of
+ Nothing -> False
+ Just ty -> isStateType ty
+
+
+-- | Flattens nested lets into a single list of bindings. The expression
+-- passed does not have to be a let expression, if it isn't an empty list of
+-- bindings is returned.
+flattenLets ::
+ CoreSyn.CoreExpr -- ^ The expression to flatten.
+ -> ([Binding], CoreSyn.CoreExpr) -- ^ The bindings and resulting expression.
+flattenLets (CoreSyn.Let binds expr) =
+ (bindings ++ bindings', expr')
+ where
+ -- Recursively flatten the contained expression
+ (bindings', expr') =flattenLets expr
+ -- Flatten our own bindings to remove the Rec / NonRec constructors
+ bindings = CoreSyn.flattenBinds [binds]
+flattenLets expr = ([], expr)
+
+-- | Create bunch of nested non-recursive let expressions from the given
+-- bindings. The first binding is bound at the highest level (and thus
+-- available in all other bindings).
+mkNonRecLets :: [Binding] -> CoreSyn.CoreExpr -> CoreSyn.CoreExpr
+mkNonRecLets bindings expr = MkCore.mkCoreLets binds expr
+ where
+ binds = map (uncurry CoreSyn.NonRec) bindings
+
+-- | A class of things that (optionally) have a core Type. The type is
+-- optional, since Type expressions don't have a type themselves.
+class TypedThing t where
+ getType :: t -> Maybe Type.Type
+
+instance TypedThing CoreSyn.CoreExpr where
+ getType (CoreSyn.Type _) = Nothing
+ getType expr = Just $ CoreUtils.exprType expr
+
+instance TypedThing CoreSyn.CoreBndr where
+ getType = return . Id.idType
+
+instance TypedThing Type.Type where
+ getType = return . id
+
+-- | Generate new uniques for all binders in the given expression.
+-- Does not support making type variables unique, though this could be
+-- supported if required (by passing a CoreSubst.Subst instead of VarEnv to
+-- genUniques' below).
+genUniques :: CoreSyn.CoreExpr -> TranslatorSession CoreSyn.CoreExpr
+genUniques = genUniques' VarEnv.emptyVarEnv
+
+-- | A helper function to generate uniques, that takes a VarEnv containing the
+-- substitutions already performed.
+genUniques' :: VarEnv.VarEnv CoreSyn.CoreBndr -> CoreSyn.CoreExpr -> TranslatorSession CoreSyn.CoreExpr
+genUniques' subst (CoreSyn.Var f) = do
+ -- Replace the binder with its new value, if applicable.
+ let f' = VarEnv.lookupWithDefaultVarEnv subst f f
+ return (CoreSyn.Var f')
+-- Leave literals untouched
+genUniques' subst (CoreSyn.Lit l) = return $ CoreSyn.Lit l
+genUniques' subst (CoreSyn.App f arg) = do
+ -- Only work on subexpressions
+ f' <- genUniques' subst f
+ arg' <- genUniques' subst arg
+ return (CoreSyn.App f' arg')
+-- Don't change type abstractions
+genUniques' subst expr@(CoreSyn.Lam bndr res) | CoreSyn.isTyVar bndr = return expr
+genUniques' subst (CoreSyn.Lam bndr res) = do
+ -- Generate a new unique for the bound variable
+ (subst', bndr') <- genUnique subst bndr
+ res' <- genUniques' subst' res
+ return (CoreSyn.Lam bndr' res')
+genUniques' subst (CoreSyn.Let (CoreSyn.NonRec bndr bound) res) = do
+ -- Make the binders unique
+ (subst', bndr') <- genUnique subst bndr
+ bound' <- genUniques' subst' bound
+ res' <- genUniques' subst' res
+ return $ CoreSyn.Let (CoreSyn.NonRec bndr' bound') res'
+genUniques' subst (CoreSyn.Let (CoreSyn.Rec binds) res) = do
+ -- Make each of the binders unique
+ (subst', bndrs') <- mapAccumLM genUnique subst (map fst binds)
+ bounds' <- mapM (genUniques' subst') (map snd binds)
+ res' <- genUniques' subst' res
+ let binds' = zip bndrs' bounds'
+ return $ CoreSyn.Let (CoreSyn.Rec binds') res'
+genUniques' subst (CoreSyn.Case scrut bndr ty alts) = do
+ -- Process the scrutinee with the original substitution, since non of the
+ -- binders bound in the Case statement is in scope in the scrutinee.
+ scrut' <- genUniques' subst scrut
+ -- Generate a new binder for the scrutinee
+ (subst', bndr') <- genUnique subst bndr
+ -- Process each of the alts
+ alts' <- mapM (doalt subst') alts
+ return $ CoreSyn.Case scrut' bndr' ty alts'