Handle data type that cannot handle with `Json.Decode.map8`.

Sample.elm

module Sample exposing (..)

import Json.Decode exposing (..)


type alias ManyFields =
    { field1 : Int
    , field2 : String
    , field3 : String
    , field4 : String
    , field5 : String
    , field6 : String
    , field7 : String
    , field8 : String
    , field9 : String
    }


manyFields : Decoder ManyFields
manyFields =
    map2 (\( f1, f2, f3, f4, f5 ) ( f6, f7, f8, f9 ) -> ManyFields f1 f2 f3 f4 f5 f6 f7 f8 f9)
        (map5 (,,,,)
            (field "field1" int)
            (field "field2" string)
            (field "field3" string)
            (field "field4" string)
            (field "field5" string)
        )
        (map4 (,,,)
            (field "field6" string)
            (field "field7" string)
            (field "field8" string)
            (field "field9" string)
        )