diff options
Diffstat (limited to 'app/Interpreter.hs')
| -rw-r--r-- | app/Interpreter.hs | 27 |
1 files changed, 8 insertions, 19 deletions
diff --git a/app/Interpreter.hs b/app/Interpreter.hs index 21340ef..7192c7b 100644 --- a/app/Interpreter.hs +++ b/app/Interpreter.hs @@ -6,9 +6,12 @@ import Code , Cho(..) , Code , Datum(..) + , Dereferenced(..) , Heap(..) , Instr(..) , Interp(..) + , InterpFn + , derefHeap , emptyHeap , emptyScope ) @@ -43,13 +46,8 @@ prove g = do Nothing -> loop -- not finished yet Just x -> return x -data Dereferenced - = FreeRef Int - | BoundRef Int Datum - | NoRef - {- Simple "fail" backtracking -} -backtrack :: PrlgEnv (Maybe (Either String Bool)) +backtrack :: InterpFn backtrack = do chos <- St.gets cho case chos @@ -61,7 +59,7 @@ backtrack = do {- if there's no other choice, answer no -} _ -> pure . Just $ Right False -proveStep :: PrlgEnv (Maybe (Either String Bool)) +proveStep :: InterpFn proveStep = St.get >>= go where finish = pure . Just @@ -76,23 +74,14 @@ proveStep = St.get >>= go Just d -> cont d _ -> ifail $ "no definition: " ++ show fn {- Unification -} - go i@Interp {cur = cur@Cho { hed = U h:hs - , gol = U g:gs - , heap = heap@(Heap _ hmap) - }} = unify h g + go i@Interp {cur = cur@Cho {hed = U h:hs, gol = U g:gs, heap = heap}} = + unify h g where uok = c i {cur = cur {hed = hs, gol = gs}} setHeap r x = c i {cur = cur {hed = hs, gol = gs, heap = writeHeap r x heap}} {- heap tools -} - deref x = - case hmap M.!? x of - Just (HeapRef x') -> - if x == x' - then FreeRef x' - else deref x' - Just x' -> BoundRef x x' - _ -> NoRef + deref = derefHeap heap writeHeap addr x (Heap nxt m) = Heap nxt (M.adjust (const x) addr m) newHeapVar h = head <$> newHeapVars 1 h newHeapVars n (Heap nxt m) = |