app "test"
    imports [Json]
    provides [main] to "./platform"

HelloWorld := {} has [Encoding {toEncoder}]

toEncoder = \@HelloWorld {} ->
    Encode.custom \bytes, fmt ->
        bytes
        |> Encode.appendWith (Encode.string "Hello, World!\n") fmt

f =
    when Str.fromUtf8 (Encode.toBytes (@HelloWorld {}) Json.toUtf8) is
        Ok s -> s
        _ -> "<bad>"

main = f
#      ^ Str