int mkor(int first, int second)
{
int eps, orend;
if ( first == NIL )
return ( second );
else if ( second == NIL )
return ( first );
else
{
/* see comment in mkopt() about why we can't use the first state
* of "first" or "second" if they satisfy "FREE_EPSILON"
*/
eps = mkstate( SYM_EPSILON );
first = link_machines( eps, first );
mkxtion( first, second );
if ( SUPER_FREE_EPSILON(finalst[first]) &&
accptnum[finalst[first]] == NIL )
{
orend = finalst[first];
mkxtion( finalst[second], orend );
}
else if ( SUPER_FREE_EPSILON(finalst[second]) &&
accptnum[finalst[second]] == NIL )
{
orend = finalst[second];
mkxtion( finalst[first], orend );
}
else
{
eps = mkstate( SYM_EPSILON );
first = link_machines( first, eps );
orend = finalst[first];
mkxtion( finalst[second], orend );
}
}
finalst[first] = orend;
return ( first );
}
/* mkposcl - convert a machine into a positive closure
*
* synopsis
* new = mkposcl( state );
*
* new - a machine matching the positive closure of "state"
*/
int
mkposcl(int state)
{
int eps;
if (SUPER_FREE_EPSILON(finalst[state])) {
mkxtion(finalst[state], state);
return state;
}
else {
eps = mkstate(SYM_EPSILON);
mkxtion(eps, state);
return link_machines(state, eps);
}
}
int mkopt(int mach)
{
int eps;
if ( ! SUPER_FREE_EPSILON(finalst[mach]) )
{
eps = mkstate( SYM_EPSILON );
mach = link_machines( mach, eps );
}
/* can't skimp on the following if FREE_EPSILON(mach) is true because
* some state interior to "mach" might point back to the beginning
* for a closure
*/
eps = mkstate( SYM_EPSILON );
mach = link_machines( eps, mach );
mkxtion( mach, finalst[mach] );
return ( mach );
}
