Define Gradient.Debug for convenient Erlang / Elixir AST lookups

lib/gradient/debug.ex

@@ -0,0 +1,39 @@
+defmodule Gradient.Debug do
+  @moduledoc ~S"""
+  Helpers for convenient debugging Erlang and Elixir ASTs.
+  """
+
+  ## TODO: specify elixir_form
+  @type elixir_form() :: any()
+  @type erlang_form() :: Gradient.SpecifyErlAst.form()
+
+  @doc ~S"""
+  Return the Elixir AST of an Elixir module.
+  """
+  @spec elixir_ast(module()) :: {:ok, [elixir_form()]}
+  def elixir_ast(mod) do
+    {:ok, {_, [{:debug_info, {:debug_info_v1, :elixir_erl, abstract_code}}]}} = 
+      :beam_lib.chunks(get_beam_path_as_charlist(mod), [:debug_info])
+    {:ok, _forms} = :elixir_erl.debug_info(:elixir_v1, :module_name, abstract_code, [])
+  end
+
+  @doc ~S"""
+  Return the Erlang AST of an Erlang or Elixir module.
+  """
+  @spec erlang_ast(module()) :: {:ok, [erlang_form()]}
+  def erlang_ast(mod) do
+    {:ok, _forms} = get_beam_path_as_charlist(mod) |> Gradient.ElixirFileUtils.get_forms_from_beam()
+  end
+
+  @doc ~S"""
+  Print module as Erlang source code.
+  """
+  @spec print_erlang(module()) :: :ok
+  def print_erlang(mod) do
+    {:ok, forms} = erlang_ast(mod)
+    IO.puts(:erl_prettypr.format(:erl_syntax.form_list(forms)))
+  end
+
+  def get_beam_path_as_charlist(mod) when is_list(mod), do: mod
+  def get_beam_path_as_charlist(mod) when is_atom(mod), do: :code.which(mod)
+end

mix.exs

@@ -16,7 +16,7 @@ defmodule Gradient.MixProject do
   # Run "mix help compile.app" to learn about applications.
   def application do
     [
-      extra_applications: [:logger]
+      extra_applications: [:logger, :syntax_tools]
     ]
   end