I’ve used that before, but the Lisp stuff still feels a lot better. I’m not just running a program and swapping out a function, but I’m using a REPL, some power

I’ve used that before, but the Lisp stuff still feels a lot better. I’m not just running a program and swapping out a function, but I’m using a REPL, some powerful introspection capabilities, a compiler, and a running system all together in a way that just works really nicely. I can add new files, import new libraries, and redefine structures. Objects that I print out in the REPL can be copied out and pasted directly into code. Rather than running the program and fixing the problems, you keep the system running the entire time you’re working on it. And the condition system provides a lot of help when you screw something up. To be clear—I’m not making the argument that people should be writing programs in Lisp. Just that there are some things to learn from the way Lisp development works. In the past, when I’ve used the various edit-and-continue tools, it felt it was just cutting some time out of the edit-compile-run cycle. The Lisp system feels more like a workbench, where you create fixtures to try things out while you are building the system.