Feature request: Add an interdiff mode

How feasible would it be to support diffing diffs?

This is related to jujutsu's interdiff.

The scenario requires 4 files: A1, A2, B1, B2, where B2 is presumably the result of rebasing the changes from A1 to A2 onto B1.

The goal is to allow comparing the difference between A1 and A2 to the differences between B1 and B2.

In this simple example above, it just looks like the juxtaposition of the two diffs.

The main difficulty would certainly be aligning the different hunks in a meaningful way, presumably using the data from the diff from A1 to B1.

Do you believe difftastic's technology to be adequate for this kind of purpose? If you deem it reasonable enough to implement, I might dive into the code and submit a PR.