module Flatten where
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
data HsValueMap mapto =
Tuple [HsValueMap mapto]
| Single mapto
- deriving (Show, Eq)
+ deriving (Show, Eq, Ord)
instance Functor HsValueMap where
fmap f (Single s) = Single (f s)
- fmap f (Tuple maps) = Tuple (fmap (fmap f) maps)
+ 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.
-- ^ map should only contain Port and other
-- HighOrder values.
}
- deriving (Show, Eq)
+ deriving (Show, Eq, Ord)
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],
hsFuncRes :: HsUseMap
-} deriving (Show, Eq)
+} deriving (Show, Eq, Ord)
type BindMap = [(
CoreBndr, -- ^ The bind name
return $ Single (SignalUse id)
typeMapToUseMap (Tuple tymaps) = do
- usemaps <- mapM typeMapToUseMap tymaps
+ usemaps <- State.mapM typeMapToUseMap tymaps
return $ Tuple usemaps
-- | Flatten a haskell function
let ((Var f), args) = collectArgs app in
flattenApplicationExpr binds (CoreUtils.exprType app) f args
where
- flattenBuildTupleExpr = error $ "Tuple construction not supported: " ++ (showSDoc $ ppr app)
- flattenApplicationExpr binds ty f args = error $ "Function application not supported: " ++ (showSDoc $ ppr app)
-
+ 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: