io action to get the current nr of choices on top level

src/Store.hs

 module Store 
   (Store,
   
-   emptyStore,addToStore,fromStore,
+   emptyStore,addToStore,fromStore, storeSize,
 
    trace,vtrace,vtrace',
 
@@ -63,4 +63,7 @@ addToStore (Store a) m x = trace ("add binding "++show m)
   (Store (insert (deref m) x a))
 
 fromStore :: Store -> OrRef -> Maybe Int
-fromStore (Store a) n = lookup (deref n) a 
\ No newline at end of file
+fromStore (Store a) n = lookup (deref n) a 
+
+storeSize :: Store -> Int
+storeSize (Store st) = size st
\ No newline at end of file

src/lib/ExternalFunctionsUnsafe.hs

@@ -128,3 +128,9 @@ try x _ = case consKind x of
 
 orsWithOrRef :: Curry a => C_OrRef -> List a -> Result a
 orsWithOrRef (C_OrRef r) xs _ = branching r (toHaskellList xs)
+
+nrOfChoices :: Result (C_IO C_Int)
+nrOfChoices st = 
+  C_IO (\ st' -> Prelude.return (IOVal (toCurry (max (size' st) (size' st')))))
+  where
+    size' = maybe 0 storeSize 

src/lib/Unsafe.curry

@@ -11,7 +11,7 @@ module Unsafe(unsafePerformIO,trace,spawnConstraint,isVar,identicalVar,
               showAnyTerm,showAnyQTerm,showAnyExpression,showAnyQExpression,
               readsAnyUnqualifiedTerm,readAnyUnqualifiedTerm,readsAnyQTerm,
               readAnyQTerm,
-              OrRef,try,ors
+              OrRef,try,orsWithOrRef,nrOfChoices
              )
  where
 
@@ -171,4 +171,7 @@ try :: a -> Either a (OrRef,[a])
 try external
 
 orsWithOrRef :: OrRef -> [a] -> a
-orsWithOrRef external
\ No newline at end of file
+orsWithOrRef external
+
+nrOfChoices :: IO Int
+nrOfChoices external
\ No newline at end of file