  Parser generators generate translators from language specifications. In many
cases, such specifications contain semantic actions written in the same
language as the generated code. Since these actions are subject to little
static checking, they are usually a source of errors which are discovered only
when generated code is compiled.
  In this paper we propose a parser generator front-end which statically checks
semantic actions for typing errors and prevents such errors from appearing in
generated code. The type checking procedure is extensible to support many
implementation languages. An extension for Java is presented along with an
extension for declarative type system descriptions.
