I got an ebook and have read it, then found there exists new edition if it, got it too, and not surprisingly found it shares much of text with previous edition. Although there exist some changes too, as new examples and added chapters.
Which would be a preferred way to read only added and updated changes? To not spend much time on rereading all the text again.
Ideal solution would be some software, desktop or mobile, or online service where I put my ebooks, and receive some sort of "Difference of the Books", book-diff*, with some way highlighted changes for proper reading. Or it may generate some "difference-ebook" for example. Preferably supporting PDF and epub formats. Perfectly allowing to navigate through combined Table of contents and skip uninteresting chapters, or showing statistics of changes, etc.
*There exists diff utility comparing texts of software source codes, but it doesn't fit for natural English texts
To the moment I tried, without satisfactory results:
There exist wdiff and dwdiff utilities intended for normal text comparison, But not only they work on plain text files, the problem is they compare only word-per-word level, and on book-size level text they simply fail to get similarities (anyway, dwdiff was better then wdiff)
anti-plagiarism software online services, but they weren't instrumental. While in the best case they would show "it was plagiarized" or not, not showing actual changes. But actually all that few freely available options I tried have failed even to find existing books as existing texts, not speaking about more fine-grained differences, highlighting, etc.