error handling

packages/python/yapex.py

@@ -24,11 +24,11 @@ class T(tuple):
 def query_prolog(engine, s):
 
     def answer( q ):
-#        try:
-        return q.next()
-#        except yap.YAPPythonException e:
-#            print e.text()
-#            return False
+        try:
+            return q.next()
+        except Exception as e:
+            print( e.args[1] )
+            return False
     
     q = engine.query(s)
     ask = True

packages/swig/yap.i

@@ -96,7 +96,7 @@ return *new YAPTerm();
     switch (e.getErrorClass()) {
     case YAPC_NO_ERROR:
       break;
-    /// bad domain, "first argument often is the predicate.
+  /// bad domain, "first argument often is the predicate.
     case DOMAIN_ERROR: {
       switch (en) {
       case DOMAIN_ERROR_OUT_OF_RANGE:
@@ -193,8 +193,7 @@ return *new YAPTerm();
       break;
     }
     PyErr_SetString(pyerr, e.text());
-    return Py_False;
-  }
+   }
 }
 
 #else