trigggrd evm bytecode decoder for list of list support

Triggerd.elm

type EvmDecoder a
    = EvmDecoder (Tape -> Result String ( Tape, a ))


type Tape
    = Tape String String


dynamicArray : EvmDecoder a -> EvmDecoder (List a)
dynamicArray decoder =
    let
        hexToLength =
            Hex.fromString >> Result.map ((*) 2)
    in
        EvmDecoder <|
            \(Tape original altered) ->
                take64 altered
                    |> hexToLength
                    |> Result.andThen
                        (\lengthIndex ->
                            String.slice lengthIndex (lengthIndex + 64) original
                                |> Hex.fromString
                                |> Result.andThen
                                    (\dataLength ->
                                        String.dropLeft (lengthIndex + 64) original
                                            |> \newAltered ->
                                                (Tape original newAltered)
                                                    |> arrayHelp [] dataLength decoder
                                                    |> Result.map (\( Tape o a, d ) -> ( Tape original (drop64 altered), d ))
                                    )
                        )


staticArray : Int -> EvmDecoder a -> EvmDecoder (List a)
staticArray len dec =
    EvmDecoder <|
        arrayHelp [] len dec


arrayHelp : List a -> Int -> EvmDecoder a -> Tape -> Result String ( Tape, List a )
arrayHelp accum len (EvmDecoder decoder) tape =
    case len of
        0 ->
            Ok ( tape, List.reverse accum )

        n ->
            decoder tape
                |> Result.andThen
                    (\( tape, val ) ->
                        arrayHelp (val :: accum) (n - 1) (EvmDecoder decoder) tape
                    )