The "statically typed" part is not a big issue (there are many statically-typed languages with REPLs, after all), but "compiled" could be. For example, while yo

The "statically typed" part is not a big issue (there are many statically-typed languages with REPLs, after all), but "compiled" could be. For example, while you can stick a read-eval-print-loop anywhere in your code when using Racket, you can't see any non-top-level bindings there, because they may or may not be there during runtime. The compiler is free to inline or fold or remove any such binding at will (as long as the behavior of the program remains the same). There's a debugger for Racket, and it's also possible to use it programmatically, but you cannot just call it like `debugger;` in JavaScript: you need to recompile a module so that it uses (a lot of) heavy instrumentation and only then you can set a breakpoint, also from the inside. I'd expect something like this: https://github.com/krixano/Lydrige https://github.com/krixano/Lydrige to have it easy in this regard - it's a statically-typed but interpreted language.