/**
* Returns the intersection between the TypeSet and the other node. The other
* node may also be a type set, in which case this function is called
* recursively to resolve the intersect.
*/
NodePtr intersect(const TypeSet::Ptr& typeSet, const NodePtr& other)
{
// Intersect all types in the type set with the other type.
NodeVector newTypes;
const NodeVector& types = typeSet->getTypes();
for (NodeVector::const_iterator it = types.begin(); it != types.end(); it++) {
NodePtr type = intersect(*it, other);
if (type->isKindOf(kInvalidType)) continue; // skip if the intersect was impossible
bool exists = false;
for (NodeVector::iterator is = newTypes.begin(); is != newTypes.end(); is++) {
if (equal(type, *is)) {
exists = true;
break;
}
}
if (!exists) newTypes.push_back(type);
}
// Return the new type set if it contains multiple types, a single type if
// there's only one left after the intersect, or InvalidType if the
// intersect yielded no types in the set.
if (newTypes.empty()) {
return NodePtr(new InvalidType);
} else if (newTypes.size() == 1) {
return newTypes.front();
} else {
TypeSet::Ptr ts(new TypeSet);
ts->setTypes(newTypes);
return ts;
}
}
/**
* Simplifies the given UnionType by removing duplicate types. If the resulting
* UnionType contains only one type, that type is returned instead of the union.
*/
NodePtr simplify(const UnionType::Ptr& input)
{
// Remove duplicate types.
NodeVector newTypes;
copyUnique(input->getTypes(), newTypes);
// Return either the new union or the only type left in the vector, if there's one.
if (newTypes.size() == 1) {
return newTypes.front();
}
UnionType::Ptr ut(new UnionType);
ut->setTypes(newTypes);
return ut;
}
/**
* Simplifies the given TypeSet by removing duplicate types. If the resulting
* TypeSet contains only one type, that type is returned instead of the set.
*/
NodePtr simplify(const TypeSet::Ptr& input)
{
// Remove duplicate types.
NodeVector newTypes;
copyUnique(input->getTypes(), newTypes);
// Return either the new set or the only type left in the set, if there's one.
if (newTypes.size() == 1) {
return newTypes.front();
}
TypeSet::Ptr ts(new TypeSet);
ts->setTypes(newTypes);
return ts;
}