static ObjectType join(ObjectType obj1, ObjectType obj2) {
if (obj1 == TOP_OBJECT || obj2 == TOP_OBJECT) {
return TOP_OBJECT;
}
NominalType nom1 = obj1.nominalType;
NominalType nom2 = obj2.nominalType;
Preconditions.checkState(areRelatedClasses(nom1, nom2));
if (obj1.equals(obj2)) {
return obj1;
}
boolean isLoose = obj1.isLoose || obj2.isLoose;
FunctionType fn = FunctionType.join(obj1.fn, obj2.fn);
PersistentMap<String, Property> props;
if (isLoose) {
fn = fn == null ? null : fn.withLoose();
props = joinPropsLoosely(obj1.props, obj2.props);
} else {
props = joinProps(obj1.props, obj2.props, nom1, nom2);
}
NominalType nominal = NominalType.pickSuperclass(nom1, nom2);
// TODO(blickly): Split TOP_OBJECT from empty object and remove this case
if (nominal == null || !nominal.isFunction()) {
fn = null;
}
return ObjectType.makeObjectType(
nominal, props, fn, isLoose, ObjectKind.join(obj1.objectKind, obj2.objectKind));
}
