[modersky]

I completely agree. We'll try to make the boundary between old and new versions as flexible as possible and both lint tools and language imports will be an important part of that.

Note also that the rewritings we consider are in their majority rather trivial. E.g. insert a ": Unit = " every time you used procedure syntax, or wrap every XML literal in xml"""...""".

The one thing that scares me a bit is experimental features. These will not port cleanly, and my advice right now would be: If you want your code to survive transitions without major rewrites, don't use experimental features. They might be tempting, but they can well be a trap down the line.