JarCastingVaporetto
Very lightweight proxy-based immutable value types for Java 8. (Compare phantom-pojos, an earlier iteration of the same idea).
Define types as follows:
public interface Address extends VType<Address> {
Collection<String> addressLines();
String postcode();
}
public interface Person extends VType<Person> {
String name();
int age();
Address address();
}
Build values like this:
Person person = Vaporetto.build(Person.class, p -> p
.with(Person::name, "Arthur Putey")
.with(Person::age, 42)
.with(Person::address, a -> a
.with(Address::addressLines, "23 Acacia Avenue", "Sunderland")
.with(Address::postcode, "VB6 5UX")));
Update values like this:
Person updated = person.update(p -> p
.with(Person::age, 43));
Reify properties into lenses like this:
Property<Person, Address> address = Property.of(Person.class, Person::address);
Property<Address, String> postcode = Property.of(Address.class, Address::postcode);
Property<Person, String> addressPostcode = address.chain(postcode);
// OR
Property<Person, String> addressPostcode = Property.of(
Property.of(Person.class, Person::Address),
Address::postcode);
assertThat(addressPostcode.get(person), equalTo("VB6 5UX"));
Person updatedPerson = addressPostcode.update(person, "RA8 81T");
assertThat(updatedPerson.address().postcode(), equalTo("RA8 81T"));