Yojson [0] provides a generic way to read JSON in OCaml. Mostly by pre-defining a type that contains any valid json value.
Right, there are some various approaches but I've had a few OCaml users tell me there were some reasons why they weren't/couldn't be used on the front end, sadly. Would really like to see some demos otherwise though
I've worked on various ways to do JSON encoding in Purescript through datatype generics, but the recent RowToList machinery lets us use record types directly. I have a post and some links collected if anyone is interested:
https://www.reddit.com/r/purescript/comments/6mss5o/new_in_p...
http://qiita.com/kimagure/items/d8a0681ae05b605c5abe