[Edu-sig] Executable pseudocode / executable flowcharts

[Jim Harrison]

> But, for visual learners, an executable flowchart can be a great tool
> (especially one that can be stepped through like a debugger, complete with
> watch windows).
> 
> Does anyone know of such a tool? If not, would there be interest in making it?
> I'm thinking some nifty features could be:

Though it's not Python, the best implementation of this sort of thing that
I've come across was Prograph, a completely visual language of flow diagrams
that compiled directly to executable code. The IDE had the best debugger
I've ever seen--stepping through the diagrams with a color change marking
the execution point, all data values visible and editable, with arbitrary
roll back and roll forward. Prograph was originally Mac-only, though now it
appears to be Windows-only. See www.pictorius.com/prograph.

> This works best for procedural programming, and I have no idea how to
> represent OOP in a flowchart.

It may be a bit heavy-duty for what you want, but you could look into the
Unified Modeling Language (UML), which collects together several styles of
flowcharting, process modeling and class diagramming in a generally OO
framework. Note that this is just a set of conventions for using diagrams in
software design, not a language that's executable in any sense. However,
there are a number of commercial CASE tools that can create code from the
diagrams, and there's a nice paper on UML and open-source at:

http://www.linuxgazette.com/issue67/gilliam.html

Jim Harrison
Univ. of Pittsburgh