Considering the complete implementation ofClite abstract syntax, parser, type checker, and semantics, identify opportunities for using templates. Reimplement the Clite interpreter in Java 1.5 in a way that takes advantage of these opporhmities.

Complete the object-oriented implementation of the Expression class and ils subclasses for Clite by redefining the type checking function V so that it becomes polymorphic over the subclasses of Expression. Also redo all the parser and type checking for expressions in this more objectoriented style, using the same approach as used in Section 13.4.1.