Reads the next object from stream, which must be an instance of java.io.PushbackReader or some derivee. stream defaults to the current value of *in*. Reads data in the edn format (subset of Clojure data): http://edn-format.org opts is a map that can include the following keys: :eof - value to return on end-of-file. When not supplied, eof throws an exception. :readers - a map of tag symbols to data-reader functions to be considered before default-data-readers. When not supplied, only the default-data-readers will be used. :default - A function of two args, that will, if present and no reader is found for a tag, be called with the tag and the value.