{"by":"wooby","id":8924337,"kids":[8924545],"parent":8924227,"text":"I agree that Feature Expressions don't add power, because yes, they are semantically equivalent to C preprocessing and orthogonal to the idea of Lisp.<p>What excites us most about Feature Macros is that they <i>do</i> add power. Here is an example of something we think is powerful from the proposal - a cross-platform macro:<p><pre><code> (case-host\n :cljs nil\n :clj (defmacro my-macro [name & body]\n (case-target\n :clj `(.println (System/-out) (str (do ~@body)))\n :cljs `(.log js/console (str (do ~@body))))))</code></pre>","time":1421862691,"type":"comment"}