Exchema

This is still a WIP. More details later =D

Installation

Add exchema to your list of dependencies in mix.exs:

def deps do
  [
    {:exchema, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/exchema.

Internals

Exchema works with some important pieces:

• Transformer It is the common definition between a coercion and a validation.

  It is a function that receives a value, a list of arguments and returns either an {:error, description} or an :ok or {:ok, new_value}

  I.E., a validation returns either an error or an ok whilist a coercion returns either a new value or an error.

• TransformerFinder This implements a function that receives a transformation definition and returns either nil or a transformer.

Work to do

• Define schema internal representation
• Create parser that parses and transforms a given input
• Create DSL to
• Allow DSL to generate struct
• Add schema-level transformations
• Implement type coercion for
  • Integer
  • Float
  • Date (ISO 8601)
  • Time (ISO 8601)
  • NaiveDateTime (ISO 8601)
  • DateTime (ISO 8601)
  • Other Schemas
• Implement transformaitons for the following libs (and extract later)
  • UUID
  • Vex (validation)

Maybe the generation of struct can be defined as a after-schema def plugin that would enable other extensions such as generating a Ecto.Schema (bonus for generating changeset validations automagically) in external libraries.