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  Definition Classes

  root

•  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 codec.map(f).encode(b) 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

  Definition Classes

  root

•  package codecs

  Provides codecs for common types and combinators for building larger codecs.

  Provides codecs for common types and combinators for building larger codecs.

  Bits and Bytes Codecs

  The simplest of the provided codecs are those that encode/decode BitVectors and ByteVectors directly. These are provided by bits and bytes methods. These codecs encode all of the bits/bytes directly in to the result and decode *all* of the remaining bits/bytes in to the result value. That is, the result of decode always returns a empty bit vector for the remaining bits.

  Similarly, fixed size alternatives are provided by the bits(size) and bytes(size) methods, which encode a fixed number of bits/bytes (or error if not provided the correct size) and decoded a fixed number of bits/bytes (or error if that many bits/bytes are not available).

  There are more specialized codecs for working with bits, including ignore and constant.

  Numeric Codecs

  There are built-in codecs for Int, Long, Float, and Double.

  There are a number of predefined integral codecs named using the form:

  [u]int$${size}[L]

  where u stands for unsigned, size is replaced by one of 8, 16, 24, 32, 64, and L stands for little-endian. For each codec of that form, the type is Codec[Int] or Codec[Long] depending on the specified size. For example, int32 supports 32-bit big-endian 2s complement signed integers, and uint16L supports 16-bit little-endian unsigned integers. Note: uint64[L] are not provided because a 64-bit unsigned integer does not fit in to a Long.

  Additionally, methods of the form [u]int[L](size: Int) and [u]long[L](size: Int) exist to build arbitrarily sized codecs, within the limitations of Int and Long.

  IEEE 754 floating point values are supported by the float, floatL, double, and doubleL codecs.

  Miscellaneous Value Codecs

  In addition to the numeric codecs, there are built-in codecs for Boolean, String, and UUID.

  Boolean values are supported by the bool codecs.

  Combinators

  There are a number of methods provided that create codecs out of other codecs. These include simple combinators such as fixedSizeBits and variableSizeBits and advanced combinators such as discriminated, which provides its own DSL for building a large codec out of many small codecs. For a list of all combinators, see the Combinators section below.

  Cryptography Codecs

  There are codecs that support working with encrypted data (encrypted), digital signatures and checksums (fixedSizeSignature and variableSizeSignature). Additionally, support for java.security.cert.Certificates is provided by certificate and x509Certificate.

  Definition Classes

  scodec

• Attempt
• BuildInfo
• Codec
• CodecTransformation
• DecodeResult
• Decoder
• DecoderFunctions
• DecodingContext
• Encoder
• EncoderFunctions
• EnrichedCoproductDecoder
• EnrichedCoproductEncoder
• EnrichedHList
• Err
• GenCodec
• HListCodecEnrichedWithHListSupport
• SizeBound
• Transform
• TransformSyntax
• Transformer
• Tuple2CodecSupport
• ValueCodecEnrichedWithGenericSupport
• ValueCodecEnrichedWithHListSupport

scodec

DecoderFunctions