Example of JSON decoding in elm

Elm JSON decode example

import Html exposing (Html, text)
import Signal exposing (constant)
import Json.Decode as Json exposing ((:=))

type alias Person =
  { name : String
  , age  : Int 
  }

personDecoder : Json.Decoder Person
personDecoder =
  Json.object2 Person
    ("name" := Json.string)
    ("age" := Json.int)

exampleString : String
exampleString =
  "{\"name\": \"john smith\", \"age\": 20}"

main : Html
main =
  case Json.decodeString personDecoder exampleString  of  
    Err _ -> text "oops"                                                                                                                                                             
    Ok  v -> text (toString v)

import Json.Decode as Json exposing ((:=)) doesn't work