Interpreter typechecks, at the cost of compositionality of RepAc

1 files changed, 46 insertions, 193 deletions

diff --git a/src/Interpreter.hs b/src/Interpreter.hs
index 8fb4a78..01d15f1 100644
--- a/src/Interpreter.hs
+++ b/src/Interpreter.hs
@@ -29,7 +29,7 @@ import AST
 import CHAD.Types
 import Data
 import Interpreter.Rep
-import Data.Bifunctor (first, bimap)
+import Data.Bifunctor (bimap)
 
 
 newtype AcM s a = AcM { unAcM :: IO a }
@@ -194,11 +194,6 @@ data PartialInvIndex n m where
   PIIxEnd :: PartialInvIndex m m
   PIIxCons :: Int -> PartialInvIndex n m -> PartialInvIndex (S n) m
 
--- | Inverted shape: the outermost dimension is at the /outside/ of this list.
-data PartialInvShape n m where
-  PIShEnd :: PartialInvShape m m
-  PIShCons :: Int -> PartialInvShape n m -> PartialInvShape (S n) m
-
 -- | Inverted shapey thing: the outermost dimension is at the /outside/ of this list.
 data Inverted (f :: Nat -> Type) n where
   InvNil :: Inverted f Z
@@ -269,52 +264,54 @@ piindexConcat (PIIxCons i pix) ix = IIxCons i (piindexConcat pix ix)
 newAcSparse :: STy t -> SNat i -> Rep (AcIdx t i) -> Rep (AcVal t i) -> IO (RepAcSparse t)
 newAcSparse typ SZ () val = case typ of
   STNil -> return ()
-  STPair{} -> newIORef =<< newAcDense typ SZ () val
+  STPair t1 t2 -> newIORef =<< (,) <$> newAcSparse t1 SZ () (fst val) <*> newAcSparse t2 SZ () (snd val)
   STMaybe t -> newIORef =<< traverse (newAcDense t SZ ()) val
-  STArr{} -> newIORef =<< newAcDense typ SZ () val
+  STArr _ t -> newIORef =<< traverse (newAcSparse t SZ ()) val
   STScal{} -> newIORef val
   STAccum{} -> error "Nested accumulators"
   STEither{} -> error "Bare Either in accumulator"
 newAcSparse typ (SS dep) idx val = case typ of
   STNil -> return ()
-  STPair{} -> newIORef =<< newAcDense typ (SS dep) idx val
+  STPair t1 t2 -> newIORef =<< case (idx, val) of
+                                 (Left idx', Left val') -> (,) <$> newAcSparse t1 dep idx' val' <*> newAcZero t2
+                                 (Right idx', Right val') -> (,) <$> newAcZero t1 <*> newAcSparse t2 dep idx' val'
+                                 _ -> error "Index/value mismatch in newAc pair"
   STMaybe t -> newIORef =<< Just <$> newAcDense t dep idx val
-  STArr{} -> newIORef =<< newAcDense typ (SS dep) idx val
+  STArr dim (t :: STy t) -> newIORef =<< newAcArray dim t (SS dep) idx val
   STScal{} -> error "Cannot index into scalar"
   STAccum{} -> error "Nested accumulators"
   STEither{} -> error "Bare Either in accumulator"
 
+newAcArray :: SNat n -> STy t -> SNat i -> Rep (AcIdx (TArr n t) i) -> Rep (AcVal (TArr n t) i) -> IO (Array n (RepAcSparse t))
+newAcArray _ t SZ _ val =
+  traverse (newAcSparse t SZ ()) val
+newAcArray dim (t :: STy t) dep@SS{} idx val = do
+  let sh = unTupRepIdx ShNil ShCons dim (fst val)
+  go dep dim idx (snd val) $ \arr position ->
+    arrayGenerateM sh (\i -> case uninvert <$> piindexMatch position (invert i) of
+                               Just i' -> return $ arr `arrayIndex` i'
+                               Nothing -> newAcZero t)
+  where
+    go :: SNat i -> SNat n -> Rep (AcIdx (TArr n t) i) -> Rep (AcValArr n t i) -> (forall m. Array m (RepAcSparse t) -> PartialInvIndex n m -> IO r) -> IO r
+    go SZ _ () val' k = arrayMapM (newAcSparse t SZ ()) val' >>= \arr -> k arr PIIxEnd
+    go (SS dep') SZ idx' val' k = newAcSparse t dep' idx' val' >>= \arr -> k (arrayUnit arr) PIIxEnd
+    go (SS dep') (SS dim') (i, idx') val' k =
+      go dep' dim' idx' val' $ \arr pish ->
+        k arr (PIIxCons (fromIntegral @Int64 @Int i) pish)
+
 newAcDense :: STy t -> SNat i -> Rep (AcIdx t i) -> Rep (AcVal t i) -> IO (RepAcDense t)
 newAcDense typ SZ () val = case typ of
-  STNil -> return ()
-  STPair t1 t2 -> (,) <$> newAcSparse t1 SZ () (fst val) <*> newAcSparse t2 SZ () (snd val)
   STEither t1 t2 -> case val of
     Left x -> Left <$> newAcSparse t1 SZ () x
     Right y -> Right <$> newAcSparse t2 SZ () y
-  STMaybe t -> traverse (newAcSparse t SZ ()) val
-  STArr _ t -> traverse (newAcSparse t SZ ()) val
-  STScal{} -> return val
-  STAccum{} -> error "Nested accumulators"
+  _ -> error "newAcDense: invalid dense type"
 newAcDense typ (SS dep) idx val = case typ of
-  STNil -> return ()
-  STPair{} -> newAcDense typ (SS dep) idx val
-  STMaybe t -> Just <$> newAcSparse t dep idx val
-  STArr dim (t :: STy t) -> do
-    let sh = unTupRepIdx ShNil ShCons dim (fst val)
-    go (SS dep) dim idx (snd val) $ \arr position ->
-      arrayGenerateM sh (\i -> case uninvert <$> piindexMatch position (invert i) of
-                                 Just i' -> return $ arr `arrayIndex` i'
-                                 Nothing -> newAcZero t)
-    where
-      go :: SNat i -> SNat n -> Rep (AcIdx (TArr n t) i) -> Rep (AcValArr n t i) -> (forall m. Array m (RepAcSparse t) -> PartialInvIndex n m -> IO r) -> IO r
-      go SZ _ () val' k = arrayMapM (newAcSparse t SZ ()) val' >>= \arr -> k arr PIIxEnd
-      go (SS dep') SZ idx' val' k = newAcSparse t dep' idx' val' >>= \arr -> k (arrayUnit arr) PIIxEnd
-      go (SS dep') (SS dim') (i, idx') val' k =
-        go dep' dim' idx' val' $ \arr pish ->
-          k arr (PIIxCons (fromIntegral @Int64 @Int i) pish)
-  STScal{} -> error "Cannot index into scalar"
-  STAccum{} -> error "Nested accumulators"
-  STEither{} -> error "Bare Either in accumulator"
+  STEither t1 t2 ->
+    case (idx, val) of
+      (Left idx', Left val') -> Left <$> newAcSparse t1 dep idx' val'
+      (Right idx', Right val') -> Right <$> newAcSparse t2 dep idx' val'
+      _ -> error "Index/value mismatch in newAc either"
+  _ -> error "newAcDense: invalid dense type"
 
 readAcSparse :: STy t -> RepAcSparse t -> IO (Rep t)
 readAcSparse typ val = case typ of
@@ -330,15 +327,10 @@ readAcSparse typ val = case typ of
 
 readAcDense :: STy t -> RepAcDense t -> IO (Rep t)
 readAcDense typ val = case typ of
-  STNil -> return ()
-  STPair t1 t2 -> (,) <$> readAcSparse t1 (fst val) <*> readAcSparse t2 (snd val)
   STEither t1 t2 -> case val of
     Left x -> Left <$> readAcSparse t1 x
     Right y -> Right <$> readAcSparse t2 y
-  STMaybe t -> traverse (readAcSparse t) val
-  STArr _ t -> traverse (readAcSparse t) val
-  STScal{} -> return val
-  STAccum{} -> error "Nested accumulators"
+  _ -> error "readAcDense: invalid dense type"
 
 accumAddSparse :: STy t -> SNat i -> RepAcSparse t -> Rep (AcIdx t i) -> Rep (AcVal t i) -> AcM s ()
 accumAddSparse typ SZ ref () val = case typ of
@@ -369,7 +361,7 @@ accumAddSparse typ SZ ref () val = case typ of
     case (shapeSize (arrayShape refs), shapeSize (arrayShape val)) of
       (_, 0) -> return ()
       (0, _) -> do
-        newrefarr <- newAcDense typ SZ () val
+        newrefarr <- traverse (newAcSparse t SZ ()) val
         join $ atomicModifyIORef' ref $ \refarr ->
                  if shapeSize (arrayShape refarr) == 0
                    then (newrefarr, return ())
@@ -410,7 +402,7 @@ accumAddSparse typ (SS dep) ref idx val = case typ of
   STArr dim (t :: STy t) -> AcM $ do
     refs <- readIORef ref
     if shapeSize (arrayShape refs) == 0
-      then do newrefarr <- newAcDense typ (SS dep) idx val
+      then do newrefarr <- newAcArray dim t (SS dep) idx val
               join $ atomicModifyIORef' ref $ \refarr ->
                        if shapeSize (arrayShape refarr) == 0
                          then (newrefarr, return ())
@@ -440,160 +432,21 @@ accumAddSparse typ (SS dep) ref idx val = case typ of
 
 accumAddDense :: forall t i s. STy t -> SNat i -> RepAcDense t -> Rep (AcIdx t i) -> Rep (AcVal t i) -> (RepAcDense t, AcM s ())
 accumAddDense typ SZ ref () val = case typ of
-  STNil -> ((), return ())
-  STPair t1 t2 ->
-    (ref, do accumAddSparse t1 SZ (fst ref) () (fst val)
-             accumAddSparse t2 SZ (snd ref) () (snd val))
-  STMaybe t ->
+  STEither t1 t2 ->
     case (ref, val) of
-      (_, Nothing) -> (ref, return ())
-      (Nothing, Just val') -> _ val'
-      (Just ref', Just val') -> _ ref' val'
-  STArr _ t -> AcM $ do
-    refs <- readIORef ref
-    case (shapeSize (arrayShape refs), shapeSize (arrayShape val)) of
-      (_, 0) -> return ()
-      (0, _) -> do
-        newrefarr <- newAcDense typ SZ () val
-        join $ atomicModifyIORef' ref $ \refarr ->
-                 if shapeSize (arrayShape refarr) == 0
-                   then (newrefarr, return ())
-                   else -- someone was faster than us in initialising the reference!
-                        (refarr, unAcM $ accumAddSparse typ SZ ref () val)  -- just try again from the start (dropping newrefarr for the GC to clean up)
-      _ | arrayShape refs == arrayShape val ->
-            sequence_ [unAcM $ accumAddSparse t SZ (arrayIndexLinear refs i) () (arrayIndexLinear val i)
-                      | i <- [0 .. shapeSize (arrayShape val) - 1]]
-        | otherwise -> error "Array shape mismatch in accum add"
-  STScal sty -> AcM $ case sty of
-    STI32 -> atomicModifyIORef' ref (\x -> (x + val, ()))
-    STI64 -> atomicModifyIORef' ref (\x -> (x + val, ()))
-    STF32 -> atomicModifyIORef' ref (\x -> (x + val, ()))
-    STF64 -> atomicModifyIORef' ref (\x -> (x + val, ()))
-    STBool -> error "Accumulator of Bool"
-  STAccum{} -> error "Nested accumulators"
-  STEither{} -> error "Bare Either in accumulator"
+      (Left ref', Left val') -> (ref, accumAddSparse t1 SZ ref' () val')
+      (Right ref', Right val') -> (ref, accumAddSparse t2 SZ ref' () val')
+      _ -> error "Mismatched Either in accumAdd"
+  _ -> error "accumAddDense: invalid dense type"
 
 accumAddDense typ (SS dep) ref idx val = case typ of
-  STNil -> return ()
-  STPair t1 t2 -> AcM $ do
-    (ref1, ref2) <- readIORef ref
-    case (idx, val) of
-      (Left idx', Left val') -> unAcM $ accumAddSparse t1 dep ref1 idx' val'
-      (Right idx', Right val') -> unAcM $ accumAddSparse t2 dep ref2 idx' val'
-      _ -> error "Index/value mismatch in pair accumulator add"
-  STMaybe t ->
-    AcM $ join $ atomicModifyIORef' ref $ \case
-                   -- Oops, ref's contents was still sparse. Have to initialise
-                   -- it first, then try again.
-                   Nothing -> (Nothing, do newac <- newAcDense t dep idx val
-                                           join $ atomicModifyIORef' ref $ \ac2 -> case ac2 of
-                                                    Nothing -> (Just newac, return ())
-                                                    Just ac2' -> bimap Just unAcM (accumAddDense t dep ac2' idx val))
-                   -- Yep, ref already had a value in there, so we can just add
-                   -- val' to it recursively.
-                   Just ac -> bimap Just unAcM (accumAddDense t dep ac idx val)
-  STArr dim (t :: STy t) -> AcM $ do
-    refs <- readIORef ref
-    if shapeSize (arrayShape refs) == 0
-      then do newrefarr <- newAcDense typ (SS dep) idx val
-              join $ atomicModifyIORef' ref $ \refarr ->
-                       if shapeSize (arrayShape refarr) == 0
-                         then (newrefarr, return ())
-                         else -- someone was faster than us in initialising the reference!
-                              (refarr, unAcM $ accumAddSparse typ (SS dep) ref idx val)  -- just try again from the start (dropping newrefarr for the GC to clean up)
-      else do let sh = unTupRepIdx ShNil ShCons dim (fst val)
-              go (SS dep) (invert sh) idx (snd val)
-                (\j index idxj valj -> unAcM $ accumAddSparse t j (refs `arrayIndex` index) idxj valj)
-                (\piix subsh val' -> unAcM $ sequence_
-                                       [accumAddSparse t SZ (refs `arrayIndex` uninvert (piindexConcat piix (invert subix)))
-                                                       () (val' `arrayIndex` subix)
-                                       | subix <- enumShape subsh])
-    where
-      go :: SNat i -> InvShape n -> Rep (AcIdx (TArr n t) i) -> Rep (AcValArr n t i)
-         -> (forall j. SNat j -> Index n -> Rep (AcIdx t j) -> Rep (AcVal t j) -> r)  -- ^ Indexing into element of the array
-         -> (forall m. PartialInvIndex n m -> Shape m -> Rep (TArr m t) -> r)  -- ^ Accumulating onto a subarray
-         -> r
-      go SZ        ish             ()        val' _  k0 = k0 PIIxEnd (uninvert ish) val'  -- ^ Ran out of AcIdx: accumulating onto subarray
-      go (SS dep') IShNil          idx'      val' kj _  = kj dep' IxNil idx' val'  -- ^ Ran out of array dimensions: accumulating into (part of) element
-      go (SS dep') (IShCons _ ish) (i, idx') val' kj k0 =
-        go dep' ish idx' val'
-          (\j index idxj valj -> kj j (IxCons index (fromIntegral @Int64 @Int i)) idxj valj)
-          (\pidxm shm valm -> k0 (PIIxCons (fromIntegral @Int64 @Int i) pidxm) shm valm)
-  STScal{} -> error "Cannot index into scalar"
-  STAccum{} -> error "Nested accumulators"
-  STEither{} -> error "Bare Either in accumulator"
-
--- accumAddVal :: forall t i s. STy t -> SNat i -> RepAc t -> Rep (AcIdx t i) -> Rep (AcVal t i) -> (RepAc t, AcM s ())
--- accumAddVal typ SZ ac () val = case typ of
---   STNil -> ((), return ())
---   STPair t1 t2 ->
---     let (ac1', m1) = accumAddVal t1 SZ (fst ac) () (fst val)
---         (ac2', m2) = accumAddVal t2 SZ (snd ac) () (snd val)
---     in ((ac1', ac2'), m1 >> m2)
---   STMaybe t -> case t of
---     STEither t1 t2 -> (ac, accumAddValME t1 t2 ac val)
---     STNil -> def ; STPair{} -> def ; STMaybe{} -> def ; STArr{} -> def ; STScal{} -> def ; STAccum{} -> def
---     where def :: (t ~ TMaybe a, RepAc (TMaybe a) ~ IORef (Maybe (RepAc a))) => (RepAc t, AcM s ())
---           def = (ac, accumAddValM t ac val)
---   STArr n t
---     | shapeSize (arrayShape ac) == 0 -> makeRepAc (STArr n t) val
---   STEither{} -> error "Bare Either in accumulator"
---   _ -> _
--- accumAddVal typ (SS dep) ac idx val = case typ of
---   STNil -> ((), return ())
---   STPair t1 t2 ->
---     case (idx, val) of
---       (Left idx', Left val') -> first (,snd ac) $ accumAddVal t1 dep (fst ac) idx' val'
---       (Right idx', Right val') -> first (fst ac,) $ accumAddVal t2 dep (snd ac) idx' val'
---       _ -> error "Inconsistent idx and val in accumulator add operation"
---   _ -> _
-
--- accumAddValME :: STy a -> STy b
---               -> IORef (Maybe (Either (RepAc a) (RepAc b)))
---               -> Maybe (Either (Rep a) (Rep b))
---               -> AcM s ()
--- accumAddValME t1 t2 ac val =
---   case val of
---     Nothing -> return ()
---     Just val' ->
---       join $ AcM $ atomicModifyIORef' ac $ \ac' -> case (ac', val') of
---                      (Nothing, _) -> (Nothing, AcM $ initAccumOrTryAgainME t1 t2 ac val' (unAcM $ accumAddValME t1 t2 ac val))
---                      (Just (Left x), Left val'1) -> first (Just . Left) $ accumAddVal t1 SZ x () val'1
---                      (Just (Right y), Right val'2) -> first (Just . Right) $ accumAddVal t2 SZ y () val'2
---                      _ -> error "Inconsistent accumulator and value in add operation on Maybe Either"
-
--- initAccumOrTryAgainME :: STy a -> STy b
---                       -> IORef (Maybe (Either (RepAc a) (RepAc b)))
---                       -> Either (Rep a) (Rep b)
---                       -> IO ()
---                       -> IO ()
--- initAccumOrTryAgainME t1 t2 ac val onRace = do
---   newContents <- case val of Left x -> Left <$> makeRepAc t1 x
---                              Right y -> Right <$> makeRepAc t2 y
---   join $ atomicModifyIORef' ac (\case Nothing -> (Just newContents, return ())
---                                       value@Just{} -> (value, onRace))
-
--- accumAddValM :: STy t
---              -> IORef (Maybe (RepAc t))
---              -> Maybe (Rep t)
---              -> AcM s ()
--- accumAddValM t ac val =
---   case val of
---     Nothing -> return ()
---     Just val' ->
---       join $ AcM $ atomicModifyIORef' ac $ \ac' -> case ac' of
---                      Nothing -> (Nothing, AcM $ initAccumOrTryAgainM t ac val' (unAcM $ accumAddValM t ac val))
---                      Just x -> first Just $ accumAddVal t SZ x () val'
+  STEither t1 t2 ->
+    case (ref, idx, val) of
+      (Left ref', Left idx', Left val') -> (Left ref', accumAddSparse t1 dep ref' idx' val')
+      (Right ref', Right idx', Right val') -> (Right ref', accumAddSparse t2 dep ref' idx' val')
+      _ -> error "Mismatched Either in accumAdd"
+  _ -> error "accumAddDense: invalid dense type"
 
--- initAccumOrTryAgainM :: STy t
---                      -> IORef (Maybe (RepAc t))
---                      -> Rep t
---                      -> IO ()
---                      -> IO ()
--- initAccumOrTryAgainM t ac val onRace = do
---   newContents <- makeRepAc t val
---   join $ atomicModifyIORef' ac (\case Nothing -> (Just newContents, return ())
---                                       value@Just{} -> (value, onRace))
 
 numericIsNum :: ScalIsNumeric st ~ True => SScalTy st -> ((Num (ScalRep st), Ord (ScalRep st)) => r) -> r
 numericIsNum STI32 = id