void
Space::_trycommit(const Choice& c, unsigned int a) {
if (a >= c.alternatives())
throw SpaceIllegalAlternative("Space::commit");
if (failed())
return;
if (Brancher* b = brancher(c._id)) {
// There is a matching brancher
if (b->commit(*this,c,a) == ES_FAILED)
fail();
}
}
NGL*
Space::ngl(const Choice& c, unsigned int a) {
if (a >= c.alternatives())
throw SpaceIllegalAlternative("Space::ngl");
if (failed())
return NULL;
if (Brancher* b = brancher(c._id)) {
// There is a matching brancher
return b->ngl(*this,c,a);
} else {
return NULL;
}
}
void
Space::print(const Choice& c, unsigned int a, std::ostream& o) const {
if (a >= c.alternatives())
throw SpaceIllegalAlternative("Space::print");
if (failed())
return;
if (Brancher* b = const_cast<Space&>(*this).brancher(c._id)) {
// There is a matching brancher
b->print(*this,c,a,o);
} else {
// There is no matching brancher!
throw SpaceNoBrancher("Space::print");
}
}
void
Space::_commit(const Choice& c, unsigned int a) {
if (a >= c.alternatives())
throw SpaceIllegalAlternative();
if (failed())
return;
/*
* Due to weakly monotonic propagators the following scenario might
* occur: a brancher has been committed with all its available
* choices. Then, propagation determines less information
* than before and the brancher now will create new choices.
* Later, during recomputation, all of these choices
* can be used together, possibly interleaved with
* choices for other branchers. That means all branchers
* must be scanned to find the matching brancher for the choice.
*
* b_commit tries to optimize scanning as it is most likely that
* recomputation does not generate new choices during recomputation
* and hence b_commit is moved from newer to older branchers.
*/
Brancher* b_old = b_commit;
// Try whether we are lucky
while (b_commit != Brancher::cast(&bl))
if (c._id != b_commit->id())
b_commit = Brancher::cast(b_commit->next());
else
goto found;
if (b_commit == Brancher::cast(&bl)) {
// We did not find the brancher, start at the beginning
b_commit = Brancher::cast(bl.next());
while (b_commit != b_old)
if (c._id != b_commit->id())
b_commit = Brancher::cast(b_commit->next());
else
goto found;
}
// There is no matching brancher!
throw SpaceNoBrancher();
found:
// There is a matching brancher
if (b_commit->commit(*this,c,a) == ES_FAILED)
fail();
}
