I've written Gists about this issue

[CMCDragonkai]

This may be interesting to you:

• https://gist.github.com/CMCDragonkai/b11dcd8ec0bf07459d197fd671738a5e - Version Control Diff, Patch and Merge Analysis (mostly Git)
• https://gist.github.com/CMCDragonkai/d266a3055735545447439f0fa662a0e1 - History Data Structures

I've also done work on a tree based data structure intended to represent arbitrary structures and allow fast structural editing: https://github.com/MatrixAI/js-tree-order-index It's not finished and is based on the paper dynamic hierarchal trees. http://www.vldb.org/pvldb/vol8/p986-finis.pdf

The same author has also got an interesting version tree data structure as well.