Behaviour for plugging custom type adapters into the CEL evaluator.

Type adapters allow Celixir to work with custom data types like protobuf messages, providing field access, has() semantics, and type conversions.

Usage

defmodule MyProtobufAdapter do
  @behaviour Celixir.TypeAdapter

  @impl true
  def native_to_value(msg) when is_struct(msg) do
    Map.from_struct(msg)
  end
  def native_to_value(v), do: v

  @impl true
  def has_field?(msg, field) when is_struct(msg) do
    atom_field = String.to_existing_atom(field)
    Map.has_key?(msg, atom_field) and Map.get(msg, atom_field) != nil
  rescue
    ArgumentError -> false
  end
  def has_field?(_, _), do: false
end

env = Celixir.Environment.new(%{msg: my_proto_msg})
      |> Celixir.Environment.set_type_adapter(MyProtobufAdapter)