We have logged your requirement in our issue tracking system. Your ticket number is WORDSNET-22730. We will further look into the details of this requirement and will keep you updated here on the status of the linked ticket.
I am afraid, it is unlikely that we will consider adding of tags to support while and do-while loops in the near future. However, it is possible to use foreach tags for looping even now. You can encapsulate required conditions for stopping of a loop into an Iterable implementation and use it with a foreach tag. Information on using of the tag can be found in the following article:
If you may have issues when implementing Iterable the way you need for looping, then please provide complete details of your use-case/scenario to be able to assist you any further.