hook called when the current perspective changes

I use perspective because I often work on projects that use several repositories. Thanks for working on it! It would be great to be able to save different bookmarks for different perspectives, and switch the set of bookmarks when the perspective changes. That could be achieved if perspective calls a hook every time the user changes the current perspective like this (using pseudo-code): perspective_changed(string current_persp, string prev_persp). Users could use this to: - save the bookmarks for prev_persp - change the file where bookmarks are read from based on the current_perp - load the new bookmarks Thoughts?