--- a/truffle/com.oracle.truffle.sl/src/com/oracle/truffle/sl/runtime/SLContext.java	Wed Sep 09 18:53:14 2015 +0200
+++ b/truffle/com.oracle.truffle.sl/src/com/oracle/truffle/sl/runtime/SLContext.java	Wed Sep 09 19:18:44 2015 +0200
@@ -53,6 +53,7 @@
 import com.oracle.truffle.sl.nodes.*;
 import com.oracle.truffle.sl.nodes.local.*;
 import com.oracle.truffle.sl.parser.*;
+import java.math.BigInteger;
 
 /**
  * The run-time state of SL during execution. One context is instantiated before any source code is
@@ -198,4 +199,13 @@
     public static DynamicObject castSLObject(Object value) {
         return LAYOUT.getType().cast(value);
     }
+
+    public static Object fromForeignValue(Object a) {
+        if (a instanceof Long || a instanceof BigInteger) {
+            return a;
+        } else if (a instanceof Number) {
+            return ((Number) a).longValue();
+        }
+        return a;
+    }
 }