state-machine-systems / jsoncodec Goto Github PK

Add fixpoint and/or lazy combinators to allow recursive structures.

Just some nice examples in the README.md would go a long way.

Love the idea of this library by the way ❤️.

One thing I was hoping to find: How do you convert a some JSON into a record? In Elm you would use something like: http://package.elm-lang.org/packages/elm-lang/core/5.1.1/Json-Decode#map or perhaps http://package.elm-lang.org/packages/NoRedInk/elm-decode-pipeline/latest

Example in Elm using elm-decode-pipeline

import Json.Decode exposing (int, string, float, Decoder)
import Json.Decode.Pipeline exposing (decode, required, optional, hardcoded)

-- basically a record in Elm
type alias User =
  { id : Int
  , email : Maybe String
  , name : String
  , percentExcited : Float
  }


userDecoder : Decoder User
userDecoder =
  decode User
    |> required "id" int
    |> required "email" (nullable string) -- `null` decodes to `Nothing`
    |> optional "name" string "(fallback if name is `null` or not present)"
    |> hardcoded 1.0

Hello @johnwright. This JSON library looks interesting! I'll read its paper, but I was wondering about its tradeoffs too (perf, size, theoretical blockers, etc.)?

The idea of having a free decoder from an encoder or vice-versa sounds pretty attractive, and if possible, I'd like the official Reason one to be free of ppx (which is needed mostly because of the usual encoding/decoding boilerplate).

It's common in JSON to use arrays as tuples, e.g.

{
  "pairs": [
    [1, 2],
    [3, 4]
  ]
}

To support this pattern, add pair, triple, quad codecs (and/or tuple2, tuple3, tuple4 etc.)

When decoding arrays as tuples, unexpected extra elements should be ignored.

JSON objects can be used like dictionaries, so add a combinator for parsing this style, e.g.

{
  "GBP": 0.77,
  "EUR": 0.84
}

let rates: codec (list (string, float)) = JsonCodec.(dict number);

Look into using Hashtbl instead of list (string, 'a).

The package name listed in bsconfig.json is bs-json-codec, while in package.json it is listed as json-codec. This causes issues with both webpack and require.js. Would it be possible to change either of them to match the other?

First, thanks for all of your hard work on this.

Useful error messages are perhaps the most important feature of any serialization/deserialization framework. What sorts of errors does this library provide?