Using Java with Other Languages - Java - page 964

return return stack . pop () + stack . pop ();

}
iif ( tok . equals ( "-" )) {
final

final Integer tos = stack . pop ();
return return stack . pop () - tos ;

}
iif ( tok . equals ( "*" )) {
return return stack . pop () * stack . pop ();

}
iif ( tok . equals ( "/" )) {
final final Integer tos = stack . pop ();

return

return stack . pop () / tos ;

}
// else ... check for other operators
// If nothing else, must be a name. get and stack its value
stack . push (( Integer ) context . getAttribute ( tok ));

}
return

return 0 ;

}

@Override
public

public Object eval ( Reader reader , ScriptContext context )
throws throws ScriptException {

System . out . println ( "CalcScriptEngine.eval()" );
// should read the file into a String, then
// return eval(scriptString, context);
throw throw new new IllegalStateException ( "eval(Reader) not written yet" );

}

@Override
public public Bindings createBindings () {

Bindings ret = new

new SimpleBindings ();

return return ret ;

}

@Override
public

public ScriptEngineFactory getFactory () {
return return factory ;

}

}

A slightly longer file is the required ScriptEngineFactory implementation: