constants for bool tags

src/GM.hs

@@ -40,6 +40,12 @@ import Core2Core
 import Core
 ----------------------------------------------------------------------------------
 
+tag_Bool_True :: Int
+tag_Bool_True = 1
+
+tag_Bool_False :: Int
+tag_Bool_False = 0
+
 {-}
 
 hdbgProg = undefined
@@ -556,12 +562,13 @@ boxBool st p = st
     where
         h = st ^. gmHeap
         (h',a) = alloc h (NConstr p' [])
-        p' = if p then 1 else 0
+        p' = if p then tag_Bool_True else tag_Bool_False
 
 unboxBool :: Addr -> GmState -> Bool
 unboxBool a st = case hLookup a h of
-        Just (NConstr 1 []) -> True
-        Just (NConstr 0 []) -> False
+        Just (NConstr t [])
+            | t == tag_Bool_True  -> True
+            | t == tag_Bool_False -> False
         Just _              -> error "unboxInt received a non-int"
         Nothing             -> error "unboxInt received an invalid address"
     where h = st ^. gmHeap