Jump / navigate to node in "Parse Tree"

[ghost]

With large parse trees it is quite laborious to navigate to a specific node that finally caused the run to fail or the last successful rule just before the fail.

A "jump to" or "navigate to" feature could be helpful. It might accept filter criteria like in #1 and a selector "first" or "last" or "mark all".

Finding the last successful rule could then be something like: navigate to "last, not type action, not rule whitespace, state success"

[fge]

OK, I'll implement that, although I am really not sure yet about the UI here :/