Multi-Form ClojureScript REPL

May 12, 2017

An update to the ClojureScript REPL has arrived, supporting multiple forms on a line.

Previously, only the first readable form would be evaluated:

cljs.user=> (+ 1 2) (str "a" "b") :hi

In the Clojure REPL, each is evaluated in sequence:

user=> (+ 1 2) (str "a" "b") :hi

The difference has been addressed with the latest ClojureScript release, 1.9.542.

This fixes an issue where text after the first form was not properly handled. So, 1] now properly produces an “Unmatched delimiter” diagnostic. Additionally, it is now possible to type :foo [, hit return, and then type 2].

What’s the big deal?

You can now paste arbitrary multi-form code into the REPL.

Let’s say you pasted this code and hit return:

(def a 1)

(def b 2)

(def c (+ a b))


Previously, the first form (def a 1) would be evaluated and then an attempt to evaluate c would result in a “Use of undeclared Var” diagnostic.

With the fix, all forms are evaluated and you get the expected 3. This makes it possible to freely paste code into a ClojureScript REPL without having to paste each form individually!

Tags: ClojureScript