Put quotes around "as", because it's a keyword.
@@ -934,7 +934,7 @@ kinds of view items:
```{.ebnf .gram}
extern_crate_decl : "extern" "crate" crate_name
-crate_name: ident | ( string_lit as ident )
+crate_name: ident | ( string_lit "as" ident )
```
An _`extern crate` declaration_ specifies a dependency on an external crate.
