Reads a single item of JSON data from a java.io.Reader. Options are key-value pairs, valid options are: :eof-error? boolean If true (default) will throw exception if the stream is empty. :eof-value Object Object to return if the stream is empty and eof-error? is false. Default is nil. :bigdec boolean If true use BigDecimal for decimal numbers instead of Double. Default is false. :key-fn function Single-argument function called on JSON property names; return value will replace the property names in the output. Default is clojure.core/identity, use clojure.core/keyword to get keyword properties. :value-fn function Function to transform values in maps ("objects" in JSON) in the output. For each JSON property, value-fn is called with two arguments: the property name (transformed by key-fn) and the value. The return value of value-fn will replace the value in the output. If value-fn returns itself, the property will be omitted from the output. The default value-fn returns the value unchanged. This option does not apply to non-map collections.