Hi,

In the past, there was a Scala implementation of a mutable double linked list, which has since been deprecated. I'm sure there were good reasons for this at the time, but I strongly believe this is an important data structure to bring into Scala. It is not unusual to need fast insertion or removal at both ends or even just at the end, but where the order matters and it's not ok to build the list in reverse and reverse it when the correct order is needed.

One could argue that in most cases the same result can be achieved by thinking more functional, however there are cases where this would be at the cost of performance. Additionally, to me Scala is a language that does not enforce a particular paradigm on the programmer, so it should be possible for a Java guy to write an algorithm in Scala the same way he would have written it imperatively, without having to massively rework and reoptimize the algorithm.

I'm creating this issue so that relevant people can (re-)evaluate the possibility of introduce back an implementation for this data structure.