Enlighten Mode displays the value of locals in realtime, as your code runs. This feature is somewhat similar to a feature in the Light Table editor.

To turn it on, issue M-x cider-enlighten-mode. Then, evaluate your functions one at a time using C-M-x or C-x C-e. Note that C-c C-k won’t work.

That’s it! Once your code executes, the regular old buffer on the left will turn into the brilliant show of lights on the right.

Enlighten Mode Disabled Enlighten Mode Enabled



To stop displaying the locals you’ll have to disable cider-enlighten-mode and reevaluate the definitions you had instrumented previously.

You can also trigger this on specific functions (without having to turn on the minor mode) by writing #light before the (def and re-evaluating it.