>You work in your real text editor and it has a connection to a persistent session of the language runtime, over which you can send fragments, lines or whole fi

>You work in your real text editor and it has a connection to a persistent session of the language runtime, over which you can send fragments, lines or whole files into. And receive data back if you wish. You can refine or replace as little or as much of the program as you want, while it is running. ...that's even closer to the style that fast compilation lends itself to