Smarter Form Targeting Is Coming to CIDER

If I had a dollar for every time someone asked on the Clojurians Slack in #cider why C-x C-e evaluated “the wrong thing”, I’d probably be writing this post from a yacht. The answer was always the same: the cursor wasn’t where CIDER expected it to be. The upcoming CIDER 2.1 release changes that - the evaluation commands now figure out which form you mean from where your cursor actually is. A bit of history Emacs has a very particular tradition when it comes to evaluating code: eval-last-sexp (the venerable C-x C-e) acts on the expression before the cursor. Not the one you’re looking at, not the one you’re inside of - the one that ends exactly where your cursor stands. SLIME follows this tradition, Emacs Lisp itself follows it, and for the past 15+ years CIDER has followed it too.1 If you grew up in Emacs, this rule is in your fingers and you’ve never once thought about it. Here’s the thing, though - most people using CIDER didn’t grow up in Emacs. And many of them never programmed in…