How Can I Deserialize Json With F#?

f#, json.net

Solution

Try removing the outer-most set of curly braces from your JSON. Right now, you have an object containing an instance of `meta`. That's probably throwing off JSON.NET. In other words, I got it to run fine by using:

let testjson = "{ 'count' : 15 }"

[Updated base on comments]

Alternately, you could keep the JSON as-is, and provide a more complex type tree in F#. For example:

type Foo =
  { meta : Meta }
and Meta =
  { count : int }

Problem

I am attempting to deserialize some very simple json into F# with Newtonsoft.Json 5.0.4: ``` #if INTERACTIVE #r "C:/Users/OCatenacci/fshacks/CreateWeeklySWEEventsEmail/packages/Newtonsoft.Json.5.0.4/lib/net40/Newtonsoft.Json.dll" #endif open System open Newtonsoft.Json type meta() = class member val count = 0 with get, set end let testjson = """{ "meta": { "count": 15 } }""" let o = JsonConvert.DeserializeObject<meta>(testjson) ``` meta always gets a 0 in the count. By the way, I was originally defining meta like this: ``` type meta = { count: int } ``` And I changed to using the Automatic property because I thought that Newtonsoft.Json might not be able to construct the object correctly. I would be surprised if my version of F#/Windows makes a difference in this case but just for sake of completeness: I'm trying this with the F# 3.0 Repl (11.0.60315.1) and I'm running on a Win7 x64 (SP1) box.

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