macros.elchemy.ex

gistfile1.txt

# Compiled using Elchemy v0.6.6
defmodule Elchemy.Macros do
  use Elchemy

  
  @moduledoc """
  This module is responsible for defining and using macros in Plugins system for Elchemy.
  To use this module you need to import it to your module and use its constructs in the
  `meta` definition of your module.
  
  @docs Macro, Do, macro, use, behaviour
  
  
  """

  def use_macro(mod) do
  module = :"Elixir.#{mod}"
  quote do
  use unquote(module)
  end
  end

  def behaviour_macro(mod) do
  module = :"Elixir.#{mod}"
  quote do
  @behaviour unquote(module)
  end
  end

  def strip_meta(mod) do
  mod
  |> Module.split
  |> Enum.drop(-1)
  |> Module.concat
  end

  @typedoc """
  Type of macro expression that go into 'meta' function in a module
  
  """
  @type macro :: :macro

  @typedoc """
  Declares a block that doesn't get evaluated eagerly but rather passed as an AST to be used later in a macro
  
  """
  @type do__(x) :: {:do, x}

  @doc """
  FFI function that creates a new macro calling an Elixir function that returns Elixir ast.
  For instance:
  
      myMacro =
          macro "ModuleContainingAstFunction" "ast_function"
  
  Notice that the function *always* returns a Macro type so that it can only be used in `meta` definition
  of a module. That ensures that macros are only called top level, everything in deeper scopes -
  like inside functions should only be handled using functions.
  
  
  """
  @spec macro(String.t, String.t) :: any
  curry macro/2
  def macro(x1, x2) do
    (Elchemy.XDebug.crash("You can't use macro in a browser")).(x1).(x2)
  end

  @doc """
  Use macro is a simple wrapper around Elixir.SpecialForms.use
  
  """
  @spec use(String.t) :: macro
  curry use/1
  def use(x1) do
    (macro("Elchemy.Macros", "use_macro")).(x1)
  end

  @doc """
  Use macro is a simple wrapper around @behaviour module attribute.
  
  """
  @spec behaviour(String.t) :: macro
  curry behaviour/1
  def behaviour(x1) do
    (macro("Elchemy.Macros", "behaviour_macro")).(x1)
  end

end