Comment by capableweb

What languages do you usually use? REPLs for languages like python and nodejs are never as integrated and well working as REPLs for lisp languages like Clojure. Probably the structure of the code that lisp almost forces you to have, makes the REPL experience much easier. Especially in Clojure where most functions are side-effect free which means you can run them out-of-context, as long as you've defined the vars it's using since before.