Utility to help writing meteor.codec.Codec, meteor.codec.Encoder and meteor.codec.Decoder.

Examples:

import meteor.syntax._
import meteor.codec._

case class Author(
  names: String,
  age: Int
)

case class Book(
  name: String,
  author: Author,
  coAuthor: Option[Author]
)

implicit val encoderForAuthor: Encoder[Author] = Encoder.instance { obj =>
  Map(
    "names" -> obj.names.asAttributeValue,
    "age" -> obj.age.asAttributeValue
  ).asAttributeValue
}

implicit val encoderForBook: Encoder[Book] = Encoder.instance { obj =>
  Map(
    "name" -> obj.names.asAttributeValue,
    "author" -> obj.age.asAttributeValue,
    "coAuthor" -> obj.age.asAttributeValue,
  ).asAttributeValue
}

implicit val decoderForAuthor: Decoder[Author] = Decoder.instance { av =>
  for {
    names <- av.getAs[String]("names")
    age <- av.getAs[Int]("age")
  } yield Author(names, age)
}

implicit val decoderForBook: Decoder[Book] = Decoder.instance { av =>
  for {
    name <- av.getAs[String]("name")
    author <- av.getAs[Author]("author")
    coAuthor <- av.getOpt[Author]("coAuthor")
  } yield Book(name, author, coAuthor)
}