cast and load transform data.
dump is a guard guard clause.
eg: atom_to_string and reverse…
defmodule Whatever.Atom do
@behaviour Ecto.Type
def type, do: :binary
def cast(atom) when is_atom(atom), do: {:ok, to_string(atom)}
def cast(string) when is_binary(string), do: {:ok, string}
def cast(_), do: :error
def load(string) when is_binary(string), do: {:ok, String.to_atom(string)}
def load(_), do: :error
def dump(string) when is_binary(string), do: {:ok, string}
def dump(_), do: :error
end
