Reputation: 3716
How to prepend (ideally O(1)
) to an immutable List (of Eclipse Collections)
Upvotes: 1
Views: 140
Reputation: 6706
There is no ImmutableList
that you can prepend to with o(1) behavior in Eclipse Collections today, but you might be able to use an ImmutableStack
for similar behavior depending on what you are trying to do.
ImmutableStack<Integer> stack = Stacks.immutable.empty();
stack = stack.push(1);
stack = stack.push(2);
stack = stack.push(3);
Assert.assertEquals(Stacks.immutable.with(1, 2, 3), stack);
// Eclipse Collections 10.x
ImmutableList<Integer> list1 = stack.toList().toImmutable();
Assert.assertEquals(Lists.immutable.with(3, 2, 1), list1);
// Eclipse Collections 11.x
ImmutableList<Integer> list2 = stack.toImmutableList();
Assert.assertEquals(Lists.immutable.with(3, 2, 1), list2);
Upvotes: 2