Don't mix up the i and dc_i variables.

[matthijs/master-project/cλash.git] / clash / CLasH / Utils / Core / CoreTools.hs

diff --git a/clash/CLasH/Utils/Core/CoreTools.hs b/clash/CLasH/Utils/Core/CoreTools.hs
index e98aec6a090ab2abc77d15251ac25850054c3185..c7bce65eeceabaa27b691ce929a8117014ff8e57 100644 (file)
--- a/clash/CLasH/Utils/Core/CoreTools.hs
+++ b/clash/CLasH/Utils/Core/CoreTools.hs
@@ -7,6 +7,7 @@ module CLasH.Utils.Core.CoreTools where
 
 --Standard modules
 import qualified Maybe
+import qualified List
 import qualified System.IO.Unsafe
 import qualified Data.Map as Map
 import qualified Data.Accessor.Monad.Trans.State as MonadState
@@ -34,6 +35,7 @@ import qualified CoreFVs
 import qualified Literal
 import qualified MkCore
 import qualified VarEnv
+import qualified Outputable
 
 -- Local imports
 import CLasH.Translator.TranslatorTypes
@@ -147,6 +149,20 @@ tfvec_elem ty = el_ty
       Nothing -> error $ "\nCoreTools.tfvec_len: Not a vector type: " ++ (pprString ty)
     [len, el_ty] = args
 
+-- | Gets the index of the given datacon in the given typed thing.
+-- Errors out if it does not occur or if the type is not an ADT.
+datacon_index :: TypedThing t => t -> DataCon.DataCon -> Int
+datacon_index tt dc =
+  case getType tt of
+    Nothing -> error $ "Getting datacon index of untyped thing? " ++ pprString tt
+    Just ty -> case Type.splitTyConApp_maybe ty of
+      Nothing -> error $ "Trying to find datacon in a type without a tycon?" ++ pprString ty
+      Just (tycon, _) -> case TyCon.tyConDataCons_maybe tycon of
+        Nothing -> error $ "Trying to find datacon in a type without datacons?" ++ pprString ty
+        Just dcs -> case List.elemIndex dc dcs of
+          Nothing -> error $ "Datacon " ++ pprString dc ++ " does not occur in type: " ++ pprString ty
+          Just i -> i
+
 -- Is the given core expression a lambda abstraction?
 is_lam :: CoreSyn.CoreExpr -> Bool
 is_lam (CoreSyn.Lam _ _) = True
@@ -347,7 +363,7 @@ mkNonRecLets bindings expr = MkCore.mkCoreLets binds expr
 
 -- | A class of things that (optionally) have a core Type. The type is
 -- optional, since Type expressions don't have a type themselves.
-class TypedThing t where
+class Outputable.Outputable t => TypedThing t where
   getType :: t -> Maybe Type.Type
 
 instance TypedThing CoreSyn.CoreExpr where
@@ -448,7 +464,7 @@ mkSelCase scrut dc_i i = do
     Just (tycon, tyargs) -> case TyCon.tyConDataCons_maybe tycon of
       -- The scrutinee type should have a single dataconstructor,
       -- otherwise we can't construct a valid selector case.
-      Just dcs | i < 0 || i >= length dcs -> error $ "\nCoreTools.mkSelCase: Creating extractor case, but datacon index is invalid." ++ error_msg
+      Just dcs | dc_i < 0 || dc_i >= length dcs -> error $ "\nCoreTools.mkSelCase: Creating extractor case, but datacon index is invalid." ++ error_msg
                | otherwise -> do
         let datacon = (dcs!!dc_i)
         let field_tys = DataCon.dataConInstOrigArgTys datacon  tyargs