Elm:
การทำงานกับ JSON

type alias UserProfile = 
    { id : Int
    , name : String
    , email : String
    }

import Json.Decode exposing (Decoder, int, string, field, map3)

userProfileDecoder : Decoder UserProfile
userProfileDecoder =
    map3 UserProfile
        (field "id" int)
        (field "name" string)
        (field "email" string)

import Json.Decode exposing (decodeString)

jsonString : String
jsonString = 
    """{"id": 1, "name": "John Doe", "email": "john@example.com"}"""

decoded : Result String UserProfile
decoded =
    decodeString userProfileDecoder jsonString

{- ตัวอย่างผลลัพธ์:
Result.Ok { id = 1, name = "John Doe", email = "[email protected]" }
-}

import Json.Encode exposing (object, int, string)

encodeUserProfile : UserProfile -> String
encodeUserProfile userProfile =
    object
        [ ("id", int userProfile.id)
        , ("name", string userProfile.name)
        , ("email", string userProfile.email)
        ]
        |> Json.Encode.encode 0

{-
การใช้งาน:
encodeUserProfile { id = 1, name = "John Doe", email = "[email protected]" }

ตัวอย่างผลลัพธ์:
"{"id":1,"name":"John Doe","email":"[email protected]"}"
-}

elm install NoRedInk/elm-json-decode-pipeline

import Json.Decode exposing (int, string, succeed)
import Json.Decode.Pipeline exposing (required, decode)

userProfileDecoder : Decoder UserProfile
userProfileDecoder =
    decode UserProfile
        |> required "id" int
        |> required "name" string
        |> required "email" string

{- ใช้ตัวถอดรหัสนี้เหมือนเดิมกับ decodeString เพื่อถอดรหัสสตริง JSON. -}