🚀 go-pugleaf

I am using lex and yacc to write a parser which converts one
data format to another. I would like this parsing routine to be
a menu sub fuction of another main program. When this routine is called by selecting the menu function for the first time,
It does its job right - translates, reports errors etc. 
However, when the routine is called again, the globals that
have been set earlier are not initialized to their appropriate values. 
For instance, When I convert File1.inp (which has errors 
in line 102) to File1.out and then I try to run the routine on 
File2.inp, It still reports errors from previous File1.inp. 
Is there any way of reinitialising the YACC globals at runtime ?