Add flattenFunction and flattenExpr.

This does not add any actual implementation for flattenExpr, just an empty
function.

This also duplicates the HsValueMap type from Translator, to prevent
dependency loops when testing.

diff --git a/Flatten.hs b/Flatten.hs
index a6b3be8f294eaed3ed07320975161c15d4fa91c1..3c5fda7b9537a801915b23ff0472720179127327 100644 (file)
--- a/Flatten.hs
+++ b/Flatten.hs
@@ -1,6 +1,15 @@
 module Flatten where
-import Translator (HsValueMap)
+import CoreSyn
+import qualified Control.Monad.State as State
 
+-- | A datatype that maps each of the single values in a haskell structure to
+-- a mapto. The map has the same structure as the haskell type mapped, ie
+-- nested tuples etc.
+data HsValueMap mapto =
+  Tuple [HsValueMap mapto]
+  | Single mapto
+  | Unused
+  deriving (Show, Eq)
 
 data FlatFunction = FlatFunction {
   args   :: [SignalDefMap],
@@ -65,4 +74,32 @@ type BindMap = [(
       [SignalUse]      -- ^ With these signals already applied to it
     )
   )]
+
+type FlattenState = State.State ([App], [CondDef], Int)
+
+-- | Flatten a haskell function
+flattenFunction ::
+  HsFunction                      -- ^ The function to flatten
+  -> CoreBind                     -- ^ The function value
+  -> FlatFunction                 -- ^ The resulting flat function
+
+flattenFunction _ (Rec _) = error "Recursive binders not supported"
+flattenFunction hsfunc bind@(NonRec var expr) =
+  FlatFunction args res apps conds
+  where
+    init_state        = ([], [], 0)
+    (fres, end_state) = State.runState (flattenExpr expr) init_state
+    (args, res)       = fres
+    (apps, conds, _)  = end_state
+
+flattenExpr ::
+  CoreExpr
+  -> FlattenState ([SignalDefMap], SignalUseMap)
+
+flattenExpr _ = do
+  return ([], Tuple [])
+
+
+
+
 -- vim: set ts=8 sw=2 sts=2 expandtab: