[elixir]map and ast toy

macro_example.ex

defmodule MacroExample do
  alias User
  alias Post

  defmacro get_struct_info(
    {:%, _, [{_, _, struct_name}, {:%{}, _, values}]}) do

    quote do
      {unquote(struct_name), unquote(values)}
    end
  end

  def user(name, email) do
    get_struct_info %User{name: name, email: email}
  end

  def post(title, body) do
    get_struct_info %Post{title: title, body: body}
  end
end

map_and_ast_toy1.ex

iex> user = %User{name: "hoge", email: "[email protected]"}
%User{email: "[email protected]", name: "hoge"}
iex> %User{user | name: "huge"}
%User{email: "[email protected]", name: "huge"}
iex> quote do: %User{user | name: "huge"}
{:%, [],
 [{:__aliases__, [alias: false], [:User]},
  {:%{}, [], [{:|, [], [{:user, [], Elixir}, [name: "huge"]]}]}]}
iex> module_name = :User
:User
iex> struct_value = :user
:user
iex> name = "huge"
"huge"
iex> q = {:%, [], [{:__aliases__, [alias: false], [module_name]}, {:%{}, [], [{:|, [], [{struct_value, [], Elixir}, [name: name]]}]}]}
{:%, [],
 [{:__aliases__, [alias: false], [:User]},
  {:%{}, [], [{:|, [], [{:user, [], Elixir}, [name: "huge"]]}]}]}
iex> Macro.to_string(q)
"%User{user | name: \"huge\"}"
iex> quote do: {:%, [], [{:__aliases__, [alias: false], [module_name]}, {:%{}, [], [{:|, [], [{struct_value, [], Elixir}, [name: name]]}]}]}
{:{}, [],
 [:%, [],
  [{:{}, [], [:__aliases__, [alias: false], [{:module_name, [], Elixir}]]},
   {:{}, [],
    [:%{}, [],
     [{:{}, [],
       [:|, [],
        [{:{}, [],
          [{:struct_value, [], Elixir}, [],
           {:__aliases__, [counter: 0], [Elixir]}]},
         [name: {:name, [], Elixir}]]]}]]}]]}
iex> quote do: unquote({:%, [], [{:__aliases__, [alias: false], [module_name]}, {:%{}, [], [{:|, [], [{struct_value, [], Elixir}, [name: name]]}]}]})
{:%, [],
 [{:__aliases__, [alias: false], [:User]},
  {:%{}, [], [{:|, [], [{:user, [], Elixir}, [name: "huge"]]}]}]}

map_and_ast_toy2.ex

iex> %User{name: "hoge", email: "[email protected]"}
%User{email: "[email protected]", name: "hoge"}
iex> quote do: %User{name: "hoge", email: "[email protected]"}
{:%, [],https://gist.github.com/darui00kara/eddf82011b1d99dd166ffb1438b0343b/edit
 [{:__aliases__, [alias: false], [:User]},
  {:%{}, [], [name: "hoge", email: "[email protected]"]}]}

omake.ex

iex> MacroExample.user "hoge", "[email protected]"
{[:User], [name: "hoge", email: "[email protected]"]}
iex> MacroExample.post "hogehoge", "foobar"
{[:Post], [title: "hogehoge", body: "foobar"]}

post.ex

defmodule Post do
  defstruct [:title, :body]
end

user.ex

defmodule User do
  defstruct [:name, :email]
end