DiffUtil and possible performance update

[brh]

In the DiffUtil code

As suggested by a teammate the areItemsTheSame and the areContentsTheSame should probably be reversed, since the compare closure seems more in line with comparing the contents. So it will look like this instead
`

        override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
            return items[oldItemPosition] == newList[newItemPosition]
        }

        override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
            return compare(items[oldItemPosition], newList[newItemPosition])
        }`

Or alternatively for more flexibility, you can change the lambda to have an additional param
compare: (T, T, Boolean)
where the Boolean lets the method know if this is the contentsTheSame check or not

Final comment, could you be making unnecessary copies of the new list
items = newList.toMutableList()
I am not sure if this is needed at all where you can just do
items = newList
Or if if has to be mutable
if (newList is MutableList) items = newList else items = newList.toMutableList()

I can send all these changes as a pull request if you like

[radoyankov]

Your teammate is right, that does make more sense. Could you make a merge request with that change? You can also include the MutableList check.

[brh]

If all ok, please post lib update to maven, jitpack, or whatever.

[radoyankov]

yea I'll do that.