Using the Java/C/C++ type system in a statechart

In YAKINDU Statechart Tools, you can import certain Java, C, or C++ files and use the functions, declarations, and types defined therein. You can use functions resp. methods from these source files as entry actions, transition triggers, etc. in your statechart – and in particular you can generate the whole statemachine in your target language, e.g., Java, C, or C++, from the statechart. I think that is really cool.

These two videos give an overview on the above: for C/C++: https://www.youtube.com/watch?v=8IxI_7xMpFY and for Java: https://www.youtube.com/watch?v=iSG2s_eUZUs

Another interesting thing is that with YAKINDU Statechart Tools, you can simulate the whole statechart interactively, including breakpoints for transitions, states, etc.

A part of YAKINDU Statechart Tools is open source: https://github.com/Yakindu/statecharts

Disclaimer: I work for itemis, the company behind YAKINDU Statechart Tools. However, I think using an actual programming language in a statechart gratifies the "interesting" requirement of the Hacker News guidelines.