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Comment by zackzackzack | Hacker News Reader

Did the speedup of script execution have other costs? One would imagine that using Clojurescript would incur some other costs somewhere. This feels like a free lunch somehow.

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ClojureScript generates a little more ephemeral garbage than native JavaScript and the Clojure data structures are slower, but in reality, the bottlenecks tend to be things which cross the DOM barrier and macros can make those bits much more efficiently. So it's not a free lunch, but it's very very cheap and tasty.

It's incompatible with standard Javascript libraries, which is why you would use Dommy because you can't use jQuery. The ClojureScript compiler is also fairly slow (due to google closure compiler I think) so even with a running jvm it takes several seconds to compile small example files. To slow for me so I switched back to CoffeScript which is lightning fast.

"It's incompatible with standard Javascript libraries, which is why you would use Dommy because you can't use jQuery."

Not true.

    (def $ js/jQuery)
    (.append ($ "body") "hello world")

The reasons you'd use Dommy over jQuery are outlined in the original post.

Not quite. The following shows what doesn't work:

    (def $ js/jQuery)
    (.each ($ "body") (fn [idx, val]
                        (.write js/document "In a lambda")))

The Google Closure Compiler munges names of functions so that any function declared in ClojureScript cannot be called from jQuery which means that no jQuery function that takes a callback can be used. And you really want to use GCC because without its dead code removal a simple helloworld.js file takes more than 700kb.

You just need to compile your ClojureScript with the popular jQuery externs file.

You can mark things so that their names aren't mudged via ^:export.

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