Support for `yield`
diff --git a/synom/src/tokens.rs b/synom/src/tokens.rs
index 655d2a7..32b71f6 100644
--- a/synom/src/tokens.rs
+++ b/synom/src/tokens.rs
@@ -190,6 +190,7 @@
         (pub struct Use                     => "use"),
         (pub struct Where                   => "where"),
         (pub struct While                   => "while"),
+        (pub struct Yield                   => "yield"),
     }
 }