On 10/02/16 12:55, Remi Forax wrote:
Java 8 to the rescue :)
The problem you have is that you don't know if the list is the result of a
calculation or if it reflect an internal state thus has to be immutable.
The idea is not to use the interface List in both cases, the result of a
calculation should be a Stream and not a List, a Stream can be seen as the
result of a calculation without specifying the collection doing the actual
storage (before 8, the JDK tends to use java.util.Enumeration and then Iterator
to represent the result of a calculation).
So you should never think that it's safe to mutate a List you get as a return
value of a method.
In perfect world yes, but in our world we have to wait for JPA and other
persistence frameworks to catch up with Java 8 and give us some
Stream-friendly APIs. For now we're still stuck with Guava ImmutableLists.
as David says it was rule out when the collection API was created as too
complex because you multiply the number of interfaces (not enough bangs for
bucks),
Pity. Now instead of nice and clean interfaces we have loads of
libraries providing the same often incompatible functionality and even
different naming for the same things. Remind of famous comics at xkcb
about 14 competing standards.
--
Regards,
Stas
