Avro

• avro is the runtime library, should be reasonably small (depends only on camlzip)
• avro-compiler can read a json schema and generate code from it

See some examples from the tests/ directory:

• tests/records.json and tests/records_test.ml that use it. you can see what the schema compiler will produce:

    $ ./compiler.sh ./tests/records.json
  (* generated by avro-compiler *)
  
  open Avro
  
  module Str_map = Map.Make(String)
  
  let schema = "{\"type\":\"record\",\"name\":\"test\",\"fields\":[{\"type\":\"long\",\"name\":\"a\"},{
  \"type\":\"string\",\"name\":\"b\"}]}"
  
  type nonrec t = { a: int64;  b: string; }
  
  let read (input:Input.t) : t =
    (let a = Input.read_int64 input in
     let b = Input.read_string input in
     { a;b })
  
  let write (out:Output.t) (self:t) : unit =
    ((let self = self.a in Output.write_int64 out self);
      (let self = self.b in Output.write_string out self);
      )

• similarly for tests/employee.json and tests/employee_test.ml that use it