+For S-Expression output, lists are printed delimited by () instead of
+[]. Objects are printed as p-lists, i.e. lists where the keys and values
+are interleaved. Keys are printed as keywords (symbols preceded by a
+colon), e.g. (:id "123" :time 54321 :from "foobar"). Null is printed as
+nil, true as t and false as nil.
+