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Instant evaluation of ClojureScript with nREPL

Today I’ve experienced a moment of pure joy — I got my editor to evaluate ClojureScript forms, and then the app (running with figwheel) would instantly reload and reflect the changes. I don’t even have to save the file.

Shaving off a second from a 5 second feedback cycle isi cool, but not a game changer. Shaving off 5 seconds from a 5 second feedback cycle changes everything.

Being able to evaluate code in the context of a running application from one’s editor with a close-to-instant feedback cycle allows a very interactive development process. For example, one can write functions and before they are even hooked in the codebase, developer can execute them against the running application state and see instant results.

It was a painful learning process to get to a point where I understood (just a bit) how to extend nREPL. I’m going to publish the examples soon. I’m a bit lazy to do it this Friday evening.

I’m also very happy that Clojurists Together will support one and only Tim Pope to work on vim Fireplace. One of the items on his plan is to look at what’s new within ClojureScript ecosystem. I really hope we’ll have a reliable setup for ClojureScript REPL via nREPL, because so far I couldn’t make it work. Here’s the link to the announcement.

Last edited on May 10, 2019