public ProgState OneStep(int index)
{
ProgState state;
try {
state = rep.getPrg(index);
}
catch (MyException.MyException e) {
throw e;
}
MyIntStack <IntStatement> stack = state.getExecStack();
if (stack.empty())
{
throw new MyException.MyException("Stack is empty!");
}
IntStatement statement = stack.pop();
ProgState newstate;
try {
newstate = statement.execute(state);
}
catch (MyException.MyException e) {
throw e;
}
return(newstate);
}
