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| author | Mirek Kratochvil <exa.exa@gmail.com> | 2022-12-14 19:47:41 +0100 |
|---|---|---|
| committer | Mirek Kratochvil <exa.exa@gmail.com> | 2022-12-14 19:47:41 +0100 |
| commit | 60ff47250b5064c38b8f4889766696cb4a5683b0 (patch) | |
| tree | eddd52364cd1b2fbfd7219061a5ed5b9c846711e /app/Code.hs | |
| parent | 32f6fe0291e289c88d29710e42da3e6aca47a3fa (diff) | |
| download | prlg-60ff47250b5064c38b8f4889766696cb4a5683b0.tar.gz prlg-60ff47250b5064c38b8f4889766696cb4a5683b0.tar.bz2 | |
slight cleanup, metacall
Diffstat (limited to 'app/Code.hs')
| -rw-r--r-- | app/Code.hs | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/app/Code.hs b/app/Code.hs index 8bea782..0556415 100644 --- a/app/Code.hs +++ b/app/Code.hs @@ -65,14 +65,30 @@ data Interp = type PrlgEnv a = StateT Interp (InputT IO) a -type BuiltinFn = PrlgEnv (Maybe (Either String Bool)) +type InterpFn = PrlgEnv (Maybe (Either String Bool)) data Builtin = - Builtin BuiltinFn + Builtin InterpFn instance Show Builtin where show _ = "Builtin _" +data Dereferenced + = FreeRef Int + | BoundRef Int Datum + | NoRef + +-- TRICKY: HeapRefs alone must not form a cycle other than the FreeRef case. +derefHeap :: Heap -> Int -> Dereferenced +derefHeap h@(Heap _ hmap) x = + case hmap M.!? x of + Just (HeapRef x') -> + if x == x' + then FreeRef x' + else derefHeap h x' + Just x' -> BoundRef x x' + _ -> NoRef + -- TODO are we actually going to use this? codeStruct :: Monad m |