A new version of Using Combine (v0.8) is now available.
This version has a number of additional notes and changes, primarily from reader feedback, and some references to Combine's changes with the release of IOS 13.2. A few more issues have been noted in the book, along with references to feedback reports sent to Apple where they may represent bugs or unexpected behavior in the current implementation.
This release also includes SVG based diagrams - so the original ASCII art diagrams are now gone, which should make that content far more accessible in the ePub format.
In addition, I've added a section on marble diagrams, specifically in how to read them and how they apply to the code and examples illustrated in this book. I originally planned on generating all the marble diagrams, but after repeated efforts at that I backed off that idea and am creating them by hand, with the help of OmniGroup's wonderful tool OmniGraffle. And yes, the source for this is also in the git repository.
For the next release, I am planning on getting back to detailing out the as-yet-unwritten section on a number of operators.
The project board at https://github.com/heckj/swiftui-notes/projects/1 also reflects all the various updates still remaining to be written.
Thank you all for supporting the development of this book!