[zozbot234]

Yes, that's really just abstracting away the control flow I was depicting in my simple diagram. It's treating "while" as a higher order function of sorts, with its own input(s) of type "data flow diagram connecting types Xs and Ys". That's the best you can do if your language only really deals in dataflow, as w/ LabVIEW ]. And that's really what leads to the difficulty you mention with pattern matching. Pattern matching on a variant record is inherently a control-flow step, even though destructuring variables in a single variant should clearly be depicted as data flow.