/**
* Verify if a clause exists that is compatible with goal. As a side effect, clauses that are not
* compatible get discarded from the currently examined family.
*
* @param goal
*/
private boolean checkCompatibility(Term goal) {
if (clauses == null) return false;
ClauseInfo clause = null;
do {
clause = (ClauseInfo) clauses.getHead();
if (goal.match(clause.getHead())) return true;
clauses = clauses.getTail();
} while (clauses != null);
return false;
}
// Updates indexes, deleting informations about the last removed clause
public void unregister(ClauseInfo ci) {
Term clause = ci.getHead();
if (clause instanceof Struct) {
Struct g = (Struct) clause.getTerm();
if (g.getArity() == 0) {
return;
}
Term t = g.getArg(0).getTerm();
if (t instanceof Var) {
numCompClausesIndex.removeShared(ci);
constantCompClausesIndex.removeShared(ci);
structCompClausesIndex.removeShared(ci);
listCompClausesList.remove(ci);
} else if (t.isAtomic()) {
if (t instanceof Number) {
numCompClausesIndex.delete((Number) t, ci);
} else if (t instanceof Struct) {
constantCompClausesIndex.delete(((Struct) t).getName(), ci);
}
} else if (t instanceof Struct) {
if (t.isList()) {
listCompClausesList.remove(ci);
} else {
structCompClausesIndex.delete(((Struct) t).getPredicateIndicator(), ci);
}
}
}
}
// Updates indexes, storing informations about the last added clause
private void register(ClauseInfo ci, boolean first) {
// See FamilyClausesList.get(Term): same concept
Term clause = ci.getHead();
if (clause instanceof Struct) {
Struct g = (Struct) clause.getTerm();
if (g.getArity() == 0) {
return;
}
Term t = g.getArg(0).getTerm();
if (t instanceof Var) {
numCompClausesIndex.insertAsShared(ci, first);
constantCompClausesIndex.insertAsShared(ci, first);
structCompClausesIndex.insertAsShared(ci, first);
if (first) {
listCompClausesList.addFirst(ci);
} else {
listCompClausesList.addLast(ci);
}
} else if (t.isAtomic()) {
if (t instanceof Number) {
numCompClausesIndex.insert((Number) t, ci, first);
} else if (t instanceof Struct) {
constantCompClausesIndex.insert(((Struct) t).getName(), ci, first);
}
} else if (t instanceof Struct) {
if (isAList((Struct) t)) {
if (first) {
listCompClausesList.addFirst(ci);
} else {
listCompClausesList.addLast(ci);
}
} else {
structCompClausesIndex.insert(((Struct) t).getPredicateIndicator(), ci, first);
}
}
}
}