Why collection literals?

Question

From the various online articles on Java 7 I have come to know that Java 7 will be having collection literals¹ like the following:

List

        

Answer 1

I think one of the reasons, is that of( ... ) will generate an unchecked warning if you would try to populate it with instances of generic objects.

The reason, ... expands to a java array, and java arrays do not like generic instances.

Here is an example from the spec that deals with this specific issue:

List> pascalsTriangle =
    [[1],
     [1, 1],
     [1, 2, 1],
     [1, 3, 3, 1],
     [1, 4, 6, 4, 1]]

There is currently no way to initialize this variable in this concise manner and without unchecked warning.