[fsfod]

You can sort of do that with some of LLVM's JIT systems https://llvm.org/docs/JITLink.html, I'm surprised that no one has yet made a edit and continue system using it.

[all2]

My parens sense is tingling. This sounds like a lisp-machine, or just standard lisp development environment.

[klibertp]

Maybe of interest: https://github.com/clasp-developers/clasp/ (Lisp env. that uses LLVM for compilation; new-ish, actively developed.) However, my impression (I didn't measure it) is that the compilation speed is an order of magnitude slower than in SBCL, never mind CCL.

[samatman]

They have! It's called Julia and it's great.