int dupmachine(int mach)
{
int i, init, state_offset;
int state = 0;
int last = lastst[mach];
for ( i = firstst[mach]; i <= last; ++i )
{
state = mkstate( transchar[i] );
if ( trans1[i] != NO_TRANSITION )
{
mkxtion( finalst[state], trans1[i] + state - i );
if ( transchar[i] == SYM_EPSILON && trans2[i] != NO_TRANSITION )
mkxtion( finalst[state], trans2[i] + state - i );
}
accptnum[state] = accptnum[i];
}
if ( state == 0 )
flexfatal( "empty machine in dupmachine()" );
state_offset = state - i + 1;
init = mach + state_offset;
firstst[init] = firstst[mach] + state_offset;
finalst[init] = finalst[mach] + state_offset;
lastst[init] = lastst[mach] + state_offset;
return ( init );
}
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 mkbranch(int first, int second)
{
int eps;
if ( first == NO_TRANSITION )
return ( second );
else if ( second == NO_TRANSITION )
return ( first );
eps = mkstate( SYM_EPSILON );
mkxtion( eps, first );
mkxtion( eps, second );
return ( eps );
}
int link_machines(int first, int last)
{
if ( first == NIL )
return ( last );
else if ( last == NIL )
return ( first );
else
{
mkxtion( finalst[first], last );
finalst[first] = finalst[last];
lastst[first] = max( lastst[first], lastst[last] );
firstst[first] = min( firstst[first], firstst[last] );
return ( first );
}
}
/* link_machines - connect two machines together
*
* synopsis
*
* new = link_machines( first, last );
*
* new - a machine constructed by connecting first to last
* first - the machine whose successor is to be last
* last - the machine whose predecessor is to be first
*
* note: this routine concatenates the machine first with the machine
* last to produce a machine new which will pattern-match first first
* and then last, and will fail if either of the sub-patterns fails.
* FIRST is set to new by the operation. last is unmolested.
*/
int
link_machines(int first, int last)
{
if (first == NIL)
return last;
else if (last == NIL)
return first;
else {
mkxtion(finalst[first], last);
finalst[first] = finalst[last];
lastst[first] = MAX(lastst[first], lastst[last]);
firstst[first] = MIN(firstst[first], firstst[last]);
return first;
}
}
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 );
}
