I'm trying to make my own tagged literals for cljs, and its a rough scene. I've probably spend 15 hours trying to get this to work properly.
The quick hack of binding cljs-data-readers is a pretty bad solution, and doesn't work with cljsbuild.
One solution is to just copy the mechanism of data_readers.clj, instead calling it cljs_data_readers.clj. That would help.
A better solution is to just pass through all the tagged literals, and resolve them on the cljs side, eg `((cljs.core/get (cljs.core/deref cljs.reader/tag-table) ~tag) ~data))
That way the definition of the tags doesn't have to be repeated twice, as is done now (once in cljs.reader, and once in the clj-side cljs.tagged-literals) .
The problem with this is that clj itself is incapable of passing through undefined tags without exploding, which is also a near showstopper. Having something like cljs_data_readers.clj would get the job done in the meantime.
(another minor issue is that the cljs reader doesn't handle namespaced symbols, so in #a/b, b is what is used as the key into cljs-data-readers)