the benefit of lisp in an editor with integrated repl environment is that you get to see immediate feedback by easily evaluating chunks of your code as you navigate it, without copying stuff back and forth between the editor and the repl

and the benefit of lisp comes from the fact that every expression is fully delineated by parentheses, so you don't need to select any text, find the start or the end of any syntactic construction, you just eval the form you're standing at and see the result

or just as easily you can wrap that form, bind the locals to test values and eval that to see what changes