Accord is a validation library written in and for Scala. Compared to JSR 303 and Scalaz validation it aims to provide the following:
- Composable: Because JSR 303 is annotation based, validation rules cannot be composed (annotations cannot receive other annotations as parameters). This is a real problem with some Scala features, for example Options or collections. Accord's validation rules are trivially composable.
- Simple: Accord provides a dead-simple story for validation rule definition by leveraging macros, as well as the validation call site (see example below).
- Self-contained: Accord is macro-based but completely self-contained, and consequently only relies on the Scala runtime and reflection libraries.
- Integrated: Other than providing its own DSL and matcher library, Accord is designed to easily integrate with other libraries, and provides out-of-the-box integration with Spring Validation, Specs2 and ScalaTest.