[tzekid]

Hmm ... how would you do that and keep the level of entry low?

Julia would come close to that - script while prototyping and compile when done.

[PuercoPop]

Several Common Lisp implementations do it, ej. SBCL. Why do you think interactivity is opposed to compilation?

I'm not too familiar with Julia but afaik it compiles the forms entered in the REPL as well.

[NilsIRL]

I've never done it and have never heard of it being done but you could replace the code a bit like a JIT compiler does it.