Add support of “with” in @throwable.

It allows to specify the post-state of data.

Example:
    @throwable T1 t1 with this->foo: true;

1 files changed, 8 insertions, 3 deletions

diff --git a/Grammar.pp b/Grammar.pp
index 4f4c6ba..9a18dab 100644
--- a/Grammar.pp
+++ b/Grammar.pp
@@ -172,9 +172,14 @@ exceptional_expression:
     exception() ( ::and:: exception() )*
 
 exception:
-    classname() <identifier> ( ::or:: classname() <identifier> )* #exception_list
-//    ( ::with:: declaration() #exception_with )?
-//                 NO
+    exception_identifier() ( ::or:: exception_identifier() )*
+    ( ::with:: exception_with() )?
+
+#exception_identifier:
+    classname() <identifier>
+
+#exception_with:
+    expression()
 
 #declaration:
     ( ::let:: #local_declaration )?