"an interactive language - one where code is often run immediately after writing" I believe you need some kind of server that is listening to the code changes

"an interactive language - one where code is often run immediately after writing" I believe you need some kind of server that is listening to the code changes and executing the program really quickly, all that will happen so quick that it will feel it's all in real time, similar to how 'live coding' works on web browser. Does that help?