Instead of putting all lines into one big chunk of code that is recompiled and rerun every time, one could instead compile it into a dynamic library with a single function that gets the current variable assignments passed as arguments, executes the single line of code and then waits for input to generate the next dynamic library, which it then loads and calls with the new variable assignment.

However, that solution would require the same level of language-specific knowledge as the modification mentioned below "Limitations" in the blog post. That's also why I never implemented the idea, despite having carried it around in my head for a few years now. Hopefully someone else will eventually get around to implementing it.