Hendrik found out:

I’ve discovered why converting the Stratego terms is slow. I was using ImploderAttachment::getCompactPositionAttachment to get the term origin. This seems to traverse the term and all it’s subterms to come up with the origin. Since I do this for every node in the tree, I’m doing a lot of the traversal many times. Is there another (faster/cached) way to get the origin, or could this be optimized?

We should switch away from that method here.

Submitted by Jeff Smits on 27 January 2017 at 12:45

Scala terms have been dropped