The semantics of flows, processes and connections along with the implementation of the
context functions and the
flowstdlib library has allowed for the
creation of a set of example flows that execute as expected.
There has pretty good overall test coverage (> 84%) that allows for safer refactoring.
The book is reasonably extensive but can always be improved. They probably need "real users" (not the author) to try to use them and flow to make the next round of improvements. There are issues in the repo and the project related to improving the book.
I have added an experimental GUI for running flows in
flowrgui that uses the rust Iced GUI toolkit.