Objective c could be. You can have undeveloped method … if you can make any unbanked message invoke debugger and continue ? Not so sure about swift playground

Objective c could be. You can have undeveloped method … if you can make any unbanked message invoke debugger and continue ? Not so sure about swift playground. One surprise may be mvs … it is not a Repl. But the idea is that the system cannot be stopped. The sysplex cannot be down because you have a sub-system or just a program error. You have to look at any core dump and fix the system whilst it is running. Obviously not development-Repl. Waterfall and punch card, thank you. But production-Repl. For production-Repl, basically all current systems needed it. There is no stop of your game world. Or may be yours but not the underlying world. It continues to run even on function upgrade or bugs etc. The real question is this production-Repl kind (not exactly Repl but the feature of keep the image running, debug or change one part of it and propagate the change without breaking the system) is really hard. Changing a s/370 control block or jes2 exit lately? Good luck and thanks you for all the fishes, that is why I go away.