在elm中使Json.Decode不区分大小写

import Json.Decode exposing (Decoder, field, succeed, string)

decodeField : String -> Decoder a -> Decoder a
decodeField fieldName decoder =
    field fieldName decoder
        |> Json.Decode.orElse (field (String.toLower fieldName) decoder)

import Json.Decode as Decode exposing (Decoder)
import Json.Decode.Extra exposing (decodeField)

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

userDecoder : Decoder User
userDecoder =
    Decode.succeed User
        |> decodeField "name" Decode.string
        |> Decode.field "age" Decode.int