Wouldn't that be something that the tooling could deal with easily? I don't know if there is anything like that yet, but the last time I took a quick look at Coalton it seemed like some basic SLIME and ASDF etc support with its own filetype and Emacs mode to go with it could be potentially useful and fun little project.
Nice, pretty much what I had in mind. I think there could be some interesting potential there tooling wise. Combining a highly dynamic interactive environment with a good statically typed language sounds fascinating to me and it's something that at least to my knowledge has never been seriously tried. Only Strongtalk comes to mind but I have no idea how it was like in practice, and I assume the type system was something closer to Java.