module Flatten where
-import Translator (HsValueMap)
+import CoreSyn
+import Control.Monad
+import qualified Var
+import qualified Type
+import qualified Name
+import qualified TyCon
+import qualified Maybe
+import Data.Traversable
+import qualified DataCon
+import qualified CoreUtils
+import Control.Applicative
+import Outputable ( showSDoc, ppr )
+import qualified Data.Foldable as Foldable
+import qualified Control.Monad.State as State
+
+-- | A datatype that maps each of the single values in a haskell structure to
+-- a mapto. The map has the same structure as the haskell type mapped, ie
+-- nested tuples etc.
+data HsValueMap mapto =
+ Tuple [HsValueMap mapto]
+ | Single mapto
+ deriving (Show, Eq)
+
+instance Functor HsValueMap where
+ fmap f (Single s) = Single (f s)
+ fmap f (Tuple maps) = Tuple (map (fmap f) maps)
+
+instance Foldable.Foldable HsValueMap where
+ foldMap f (Single s) = f s
+ -- The first foldMap folds a list of HsValueMaps, the second foldMap folds
+ -- each of the HsValueMaps in that list
+ foldMap f (Tuple maps) = Foldable.foldMap (Foldable.foldMap f) maps
+
+instance Traversable HsValueMap where
+ traverse f (Single s) = Single <$> f s
+ traverse f (Tuple maps) = Tuple <$> (traverse (traverse f) maps)
+
+data PassState s x = PassState (s -> (s, x))
+
+instance Functor (PassState s) where
+ fmap f (PassState a) = PassState (\s -> let (s', a') = a s in (s', f a'))
+
+instance Applicative (PassState s) where
+ pure x = PassState (\s -> (s, x))
+ PassState f <*> PassState x = PassState (\s -> let (s', f') = f s; (s'', x') = x s' in (s'', f' x'))
+
+-- | Creates a HsValueMap with the same structure as the given type, using the
+-- given function for mapping the single types.
+mkHsValueMap ::
+ Type.Type -- ^ The type to map to a HsValueMap
+ -> HsValueMap Type.Type -- ^ The resulting map and state
+
+mkHsValueMap ty =
+ case Type.splitTyConApp_maybe ty of
+ Just (tycon, args) ->
+ if (TyCon.isTupleTyCon tycon)
+ then
+ Tuple (map mkHsValueMap args)
+ else
+ Single ty
+ Nothing -> Single ty
+
+-- Extract the arguments from a data constructor application (that is, the
+-- normal args, leaving out the type args).
+dataConAppArgs :: DataCon.DataCon -> [CoreExpr] -> [CoreExpr]
+dataConAppArgs dc args =
+ drop tycount args
+ where
+ tycount = length $ DataCon.dataConAllTyVars dc
+
data FlatFunction = FlatFunction {
args :: [SignalDefMap],
res :: SignalUseMap,
--sigs :: [SignalDef],
- apps :: [App],
+ apps :: [FApp],
conds :: [CondDef]
} deriving (Show, Eq)
type SignalUseMap = HsValueMap SignalUse
type SignalDefMap = HsValueMap SignalDef
+useMapToDefMap :: SignalUseMap -> SignalDefMap
+useMapToDefMap = fmap (\(SignalUse u) -> SignalDef u)
+
+defMapToUseMap :: SignalDefMap -> SignalUseMap
+defMapToUseMap = fmap (\(SignalDef u) -> SignalUse u)
+
+
+type SignalId = Int
data SignalUse = SignalUse {
- sigUseId :: Int
+ sigUseId :: SignalId
} deriving (Show, Eq)
data SignalDef = SignalDef {
- sigDefId :: Int
+ sigDefId :: SignalId
} deriving (Show, Eq)
-data App = App {
+data FApp = FApp {
appFunc :: HsFunction,
appArgs :: [SignalUseMap],
appRes :: SignalDefMap
type HsUseMap = HsValueMap HsValueUse
+-- | Builds a HsUseMap with the same structure has the given HsValueMap in
+-- which all the Single elements are marked as State, with increasing state
+-- numbers.
+useAsState :: HsValueMap a -> HsUseMap
+useAsState map =
+ map'
+ where
+ -- Traverse the existing map, resulting in a function that maps an initial
+ -- state number to the final state number and the new map
+ PassState f = traverse asState map
+ -- Run this function to get the new map
+ (_, map') = f 0
+ -- This function maps each element to a State with a unique number, by
+ -- incrementing the state count.
+ asState x = PassState (\s -> (s+1, State s))
+
+-- | Builds a HsUseMap with the same structure has the given HsValueMap in
+-- which all the Single elements are marked as Port.
+useAsPort :: HsValueMap a -> HsUseMap
+useAsPort map = fmap (\x -> Port) map
+
data HsFunction = HsFunction {
hsFuncName :: String,
hsFuncArgs :: [HsUseMap],
} deriving (Show, Eq)
type BindMap = [(
- String, -- ^ The bind name
+ CoreBndr, -- ^ The bind name
Either -- ^ The bind value which is either
- SignalUse -- ^ a signal
+ SignalUseMap -- ^ a signal
(
HsValueUse, -- ^ or a HighOrder function
[SignalUse] -- ^ With these signals already applied to it
)
)]
+
+type FlattenState = State.State ([FApp], [CondDef], SignalId)
+
+-- | Add an application to the current FlattenState
+addApp :: FApp -> FlattenState ()
+addApp a = do
+ (apps, conds, n) <- State.get
+ State.put (a:apps, conds, n)
+
+-- | Add a conditional definition to the current FlattenState
+addCondDef :: CondDef -> FlattenState ()
+addCondDef c = do
+ (apps, conds, n) <- State.get
+ State.put (apps, c:conds, n)
+
+-- | Generates a new signal id, which is unique within the current flattening.
+genSignalId :: FlattenState SignalId
+genSignalId = do
+ (apps, conds, n) <- State.get
+ State.put (apps, conds, n+1)
+ return n
+
+genSignalUses ::
+ Type.Type
+ -> FlattenState SignalUseMap
+
+genSignalUses ty = do
+ typeMapToUseMap tymap
+ where
+ -- First generate a map with the right structure containing the types
+ tymap = mkHsValueMap ty
+
+typeMapToUseMap ::
+ HsValueMap Type.Type
+ -> FlattenState SignalUseMap
+
+typeMapToUseMap (Single ty) = do
+ id <- genSignalId
+ return $ Single (SignalUse id)
+
+typeMapToUseMap (Tuple tymaps) = do
+ usemaps <- State.mapM typeMapToUseMap tymaps
+ return $ Tuple usemaps
+
+-- | Flatten a haskell function
+flattenFunction ::
+ HsFunction -- ^ The function to flatten
+ -> CoreBind -- ^ The function value
+ -> FlatFunction -- ^ The resulting flat function
+
+flattenFunction _ (Rec _) = error "Recursive binders not supported"
+flattenFunction hsfunc bind@(NonRec var expr) =
+ FlatFunction args res apps conds
+ where
+ init_state = ([], [], 0)
+ (fres, end_state) = State.runState (flattenExpr [] expr) init_state
+ (args, res) = fres
+ (apps, conds, _) = end_state
+
+flattenExpr ::
+ BindMap
+ -> CoreExpr
+ -> FlattenState ([SignalDefMap], SignalUseMap)
+
+flattenExpr binds lam@(Lam b expr) = do
+ -- Find the type of the binder
+ let (arg_ty, _) = Type.splitFunTy (CoreUtils.exprType lam)
+ -- Create signal names for the binder
+ defs <- genSignalUses arg_ty
+ let binds' = (b, Left defs):binds
+ (args, res) <- flattenExpr binds' expr
+ return ((useMapToDefMap defs) : args, res)
+
+flattenExpr binds (Var id) =
+ case bind of
+ Left sig_use -> return ([], sig_use)
+ Right _ -> error "Higher order functions not supported."
+ where
+ bind = Maybe.fromMaybe
+ (error $ "Argument " ++ Name.getOccString id ++ "is unknown")
+ (lookup id binds)
+
+flattenExpr binds app@(App _ _) = do
+ -- Is this a data constructor application?
+ case CoreUtils.exprIsConApp_maybe app of
+ -- Is this a tuple construction?
+ Just (dc, args) -> if DataCon.isTupleCon dc
+ then
+ flattenBuildTupleExpr binds (dataConAppArgs dc args)
+ else
+ error $ "Data constructors other than tuples not supported: " ++ (showSDoc $ ppr app)
+ otherwise ->
+ -- Normal function application
+ let ((Var f), args) = collectArgs app in
+ flattenApplicationExpr binds (CoreUtils.exprType app) f args
+ where
+ flattenBuildTupleExpr binds args = do
+ -- Flatten each of our args
+ flat_args <- (State.mapM (flattenExpr binds) args)
+ -- Check and split each of the arguments
+ let (_, arg_ress) = unzip (zipWith checkArg args flat_args)
+ let res = Tuple arg_ress
+ return ([], res)
+
+ -- | Flatten a normal application expression
+ flattenApplicationExpr binds ty f args = do
+ -- Find the function to call
+ let func = appToHsFunction ty f args
+ -- Flatten each of our args
+ flat_args <- (State.mapM (flattenExpr binds) args)
+ -- Check and split each of the arguments
+ let (_, arg_ress) = unzip (zipWith checkArg args flat_args)
+ -- Generate signals for our result
+ res <- genSignalUses ty
+ -- Create the function application
+ let app = FApp {
+ appFunc = func,
+ appArgs = arg_ress,
+ appRes = useMapToDefMap res
+ }
+ addApp app
+ return ([], res)
+ -- | Check a flattened expression to see if it is valid to use as a
+ -- function argument. The first argument is the original expression for
+ -- use in the error message.
+ checkArg arg flat =
+ let (args, res) = flat in
+ if not (null args)
+ then error $ "Passing lambda expression or function as a function argument not supported: " ++ (showSDoc $ ppr arg)
+ else flat
+
+flattenExpr binds l@(Let (NonRec b bexpr) expr) = do
+ (b_args, b_res) <- flattenExpr binds bexpr
+ if not (null b_args)
+ then
+ error $ "Higher order functions not supported in let expression: " ++ (showSDoc $ ppr l)
+ else
+ let binds' = (b, Left b_res) : binds in
+ flattenExpr binds' expr
+
+flattenExpr binds l@(Let (Rec _) _) = error $ "Recursive let definitions not supported: " ++ (showSDoc $ ppr l)
+
+flattenExpr binds expr@(Case (Var v) b _ alts) =
+ case alts of
+ [alt] -> flattenSingleAltCaseExpr binds v b alt
+ otherwise -> error $ "Multiple alternative case expression not supported: " ++ (showSDoc $ ppr expr)
+ where
+ flattenSingleAltCaseExpr ::
+ BindMap
+ -- A list of bindings in effect
+ -> Var.Var -- The scrutinee
+ -> CoreBndr -- The binder to bind the scrutinee to
+ -> CoreAlt -- The single alternative
+ -> FlattenState ( [SignalDefMap], SignalUseMap)
+ -- See expandExpr
+ flattenSingleAltCaseExpr binds v b alt@(DataAlt datacon, bind_vars, expr) =
+ if not (DataCon.isTupleCon datacon)
+ then
+ error $ "Dataconstructors other than tuple constructors not supported in case pattern of alternative: " ++ (showSDoc $ ppr alt)
+ else
+ let
+ -- Lookup the scrutinee (which must be a variable bound to a tuple) in
+ -- the existing bindings list and get the portname map for each of
+ -- it's elements.
+ Left (Tuple tuple_sigs) = Maybe.fromMaybe
+ (error $ "Case expression uses unknown scrutinee " ++ Name.getOccString v)
+ (lookup v binds)
+ -- TODO include b in the binds list
+ -- Merge our existing binds with the new binds.
+ binds' = (zip bind_vars (map Left tuple_sigs)) ++ binds
+ in
+ -- Expand the expression with the new binds list
+ flattenExpr binds' expr
+ flattenSingleAltCaseExpr _ _ _ alt = error $ "Case patterns other than data constructors not supported in case alternative: " ++ (showSDoc $ ppr alt)
+
+
+
+flattenExpr _ _ = do
+ return ([], Tuple [])
+
+appToHsFunction ::
+ Type.Type -- ^ The return type
+ -> Var.Var -- ^ The function to call
+ -> [CoreExpr] -- ^ The function arguments
+ -> HsFunction -- ^ The needed HsFunction
+
+appToHsFunction ty f args =
+ HsFunction hsname hsargs hsres
+ where
+ hsname = Name.getOccString f
+ hsargs = map (useAsPort . mkHsValueMap . CoreUtils.exprType) args
+ hsres = useAsPort (mkHsValueMap ty)
+
-- vim: set ts=8 sw=2 sts=2 expandtab: