Yojson to parse int64 (ocaml)

Question

As of my understanding this {"xxx": 1000000000000000} is valid right?

Not sure how to parse it with Yojson.Safe. I'm looking for something like _ `Int64 of int64 _ , but none provided, there are only _ `Int of int _ and _ `Intlit of string _ on the api.

Edit, this is my problem

let x = "{\"xxx\": 10000000000000}"
let json = Yojson.Safe.from_string x
match json with `Assoc [("xxx", `Intlit yyy)] -> yyy | _ -> assert false

It won't match because the type of json is

val json : Yojson.Safe.json = `Assoc [("xxx", `Int 10000000000000)]

Daniel Bünzli · Accepted Answer · 2014-03-07T14:47:11.593

3

It seems Yojson returns Int if it fits in an OCaml int and `Intlit otherwise so you need to treat all the cases:

match json with 
| `Assoc [("xxx", `Intlit lit)] -> Int64.of_string lit
| `Assoc [("xxx", `Int i)] -> Int64.of_int i

edited Mar 07 '14 at 14:47

answered Mar 07 '14 at 10:19

Daniel Bünzli

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Ok, completely changed my answer. – Daniel Bünzli Mar 07 '14 at 14:47
Ah, I see, Yojson.Safe will convert that to `Intlit if the number is bigger than `Int. That's what I missed. – romerun Mar 08 '14 at 03:51

Yojson to parse int64 (ocaml)

1 Answers1