---

RFC 7049

The Concise Binary Object Representation (CBOR) is a data format whose design goals include the possibility of extremely small code size, fairly small message size, and extensibility without the need for version negotiation. These design goals make it different from earlier binary serializations such as ASN.1 and MessagePack.

Getting Started

Installation

elm install elm-toulouse/cbor

Usage

import Cbor.Decode as D
import Cbor.Encode as E

type alias Album =
    { artist : String
    , title : String
    , genre : Maybe Genre
    , tracks : List Track
    , label : Maybe String
    }


type alias Track =
    { title : String
    , duration : Int
    }


type Genre
    = Electronic
    | Pop
    | Jazz
    | Metal


encodeAlbum : Album -> E.Encoder
encodeAlbum =
    E.record E.int <|
        E.fields
            >> E.field 0 E.string .artist
            >> E.field 1 E.string .title
            >> E.optionalField 2 encodeGenre .genre
            >> E.field 3 (E.list encodeTrack) .tracks
            >> E.optionalField 4 E.string .label


decodeAlbum : D.Decoder Album
decodeAlbum =
    D.record D.int Album <|
        D.fields
            >> D.field 0 D.string
            >> D.field 1 D.string
            >> D.optionalField 2 decodeGenre
            >> D.field 3 (D.list decodeTrack)
            >> D.optionalField 4 D.string


encodeTrack : Track -> E.Encoder
encodeTrack =
    E.tuple <|
        E.elems
            >> E.elem E.string .title
            >> E.elem E.int .duration


decodeTrack : D.Decoder Track
decodeTrack =
    D.tuple Track <|
        D.elems
            >> D.elem D.string
            >> D.elem D.int


encodeGenre : Genre -> E.Encoder
encodeGenre genre =
    case genre of
        Electronic ->
            E.int 0

        Pop ->
            E.int 1

        Jazz ->
            E.int 2

        Metal ->
            E.int 3


decodeGenre : D.Decoder Genre
decodeGenre =
    D.int
        |> D.andThen
            (\s ->
                case s of
                    0 ->
                        D.succeed Electronic

                    1 ->
                        D.succeed Pop

                    2 ->
                        D.succeed Jazz

                    3 ->
                        D.succeed Metal

                    _ ->
                        D.fail
            )

Changelog

CHANGELOG.md