• package root
  • package scala
  • package scodec

    Combinator library for working with binary data.

    Combinator library for working with binary data.

    The primary abstraction of this library is Codec, which provides the ability to encode/decode values to/from binary.

    There are more general abstractions though, such as Encoder and Decoder. There's also GenCodec which extends both Encoder and Decoder but allows the types to vary. Given these more general abstractions, a Codec[A] can be represented as a GenCodec[A, A].

    The more general abstractions are important because they allow operations on codecs that would not otherwise be possible. For example, given a Codec[A], mapping a function A => B over the codec yields a GenCodec[A, B]. Without the more general abstractions, map is impossible to define (e.g., how would be implemented?). Given a GenCodec[A, B], the encoding functionality can be ignored by treating it as a Decoder[B], or the encoding type can be changed via contramap. If after further transformations, the two types to GenCodec are equal, we can reconstitute a Codec from the GenCodec by calling fuse.

    See the codecs package object for pre-defined codecs for many common data types and combinators for building larger codecs out of smaller ones.

    For the categorically minded, note the following:

    • Decoder is a monad
    • Encoder is a contravariant functor
    • GenCodec is a profunctor
    • Codec is an invariant functor

root package

package root