Optional semicolons

demo-optional-semi.patch

diff --git a/examples/demo.rs b/examples/demo.rs
index ff14042..2ec627d 100644
--- a/examples/demo.rs
+++ b/examples/demo.rs
@@ -150,9 +150,14 @@ mod parser {
             statements[s] => Program { stmts: s }
         }
 
+        optionalSemi: () {
+            => (),
+            Semi => (),
+        }
+
         statements: Vec<Expr> {
             => vec![],
-            statements[mut st] assign[e] Semi => {
+            statements[mut st] assign[e] optionalSemi => {
                 st.push(e);
                 st
             }