module Flatten where
import CoreSyn
+import Control.Monad
+import qualified Var
import qualified Type
-import qualified TyCon
+import qualified Name
+import qualified Maybe
+import qualified DataCon
import qualified CoreUtils
+import Control.Applicative
+import Outputable ( showSDoc, ppr )
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)
+import HsValueMap
+import TranslatorTypes
+import FlattenTypes
+-- 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
-
--- | 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
-
-data FlatFunction = FlatFunction {
- args :: [SignalDefMap],
- res :: SignalUseMap,
- --sigs :: [SignalDef],
- apps :: [App],
- conds :: [CondDef]
-} deriving (Show, Eq)
-
-type SignalUseMap = HsValueMap SignalUse
-type SignalDefMap = HsValueMap SignalDef
-
-type SignalId = Int
-data SignalUse = SignalUse {
- sigUseId :: SignalId
-} deriving (Show, Eq)
-
-data SignalDef = SignalDef {
- sigDefId :: SignalId
-} deriving (Show, Eq)
-
-data App = App {
- appFunc :: HsFunction,
- appArgs :: [SignalUseMap],
- appRes :: SignalDefMap
-} deriving (Show, Eq)
-
-data CondDef = CondDef {
- cond :: SignalUse,
- high :: SignalUse,
- low :: SignalUse,
- condRes :: SignalDef
-} deriving (Show, Eq)
-
--- | How is a given (single) value in a function's type (ie, argument or
--- return value) used?
-data HsValueUse =
- Port -- ^ Use it as a port (input or output)
- | State Int -- ^ Use it as state (input or output). The int is used to
- -- match input state to output state.
- | HighOrder { -- ^ Use it as a high order function input
- hoName :: String, -- ^ Which function is passed in?
- hoArgs :: [HsUseMap] -- ^ Which arguments are already applied? This
- -- ^ map should only contain Port and other
- -- HighOrder values.
- }
- deriving (Show, Eq)
-
-type HsUseMap = HsValueMap HsValueUse
-
-data HsFunction = HsFunction {
- hsFuncName :: String,
- hsFuncArgs :: [HsUseMap],
- hsFuncRes :: HsUseMap
-} deriving (Show, Eq)
-
-type BindMap = [(
- CoreBndr, -- ^ The bind name
- Either -- ^ The bind value which is either
- SignalUseMap -- ^ a signal
- (
- HsValueUse, -- ^ or a HighOrder function
- [SignalUse] -- ^ With these signals already applied to it
- )
- )]
-
-type FlattenState = State.State ([App], [CondDef], SignalId)
-
--- | Add an application to the current FlattenState
-addApp :: App -> 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 ::
+genSignals ::
Type.Type
- -> FlattenState SignalUseMap
+ -> FlattenState (SignalMap UnnamedSignal)
-genSignalUses ty = do
+genSignals ty = do
typeMapToUseMap tymap
where
-- First generate a map with the right structure containing the types
typeMapToUseMap ::
HsValueMap Type.Type
- -> FlattenState SignalUseMap
+ -> FlattenState (SignalMap UnnamedSignal)
typeMapToUseMap (Single ty) = do
- id <- genSignalId
- return $ Single (SignalUse id)
+ id <- genSignalId ty
+ return $ Single id
typeMapToUseMap (Tuple tymaps) = do
- usemaps <- mapM typeMapToUseMap tymaps
+ usemaps <- State.mapM typeMapToUseMap tymaps
return $ Tuple usemaps
-- | Flatten a haskell function
flattenFunction _ (Rec _) = error "Recursive binders not supported"
flattenFunction hsfunc bind@(NonRec var expr) =
- FlatFunction args res apps conds
+ FlatFunction args res apps conds sigs
where
- init_state = ([], [], 0)
+ init_state = ([], [], [], 0)
(fres, end_state) = State.runState (flattenExpr [] expr) init_state
(args, res) = fres
- (apps, conds, _) = end_state
+ (apps, conds, sigs, _) = end_state
flattenExpr ::
BindMap
-> CoreExpr
- -> FlattenState ([SignalDefMap], SignalUseMap)
+ -> FlattenState ([SignalMap UnnamedSignal], (SignalMap UnnamedSignal))
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
+ defs <- genSignals arg_ty
let binds' = (b, Left defs):binds
- flattenExpr binds' expr
+ (args, res) <- flattenExpr binds' expr
+ return (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 <- genSignals ty
+ -- Create the function application
+ let app = FApp {
+ appFunc = func,
+ appArgs = arg_ress,
+ appRes = 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 ( [SignalMap UnnamedSignal], SignalMap UnnamedSignal)
+ -- 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: