defmodule Asm do
  use Constants

  @moduledoc """
  Asm aimed at implementing an inline assembler.

  Currently, it provides the following:

  * `is_int64` macro that can be used in `when` clauses to judge that a value is within INT64.
  * `is_uint64` macro that can be used in `when` clauses to judge that a value is within UINT64.
  * `is_bignum` macro that can be used in `when` clauses to judge that a value needs BigNum representation, that is, it is an integer but not within INT64 nor UINT64.
  * `max_int` is the constant value of maxium of INT64.
  * `min_int` is the constant value of minimum of INT64.
  * `max_uint` is the constant value of maxium of UINT64.
  * `min_uint` is the constant value of minimum of UINT64.
  """

  @name :max_int
  @value 0x7fff_ffff_ffff_ffff

  @name :min_int
  @value -0x8000_0000_0000_0000

  @name :max_uint
  @value 0xffff_ffff_ffff_ffff

  @name :min_uint
  @value 0

  @doc """
  is_int64(value) returns true if the value is a signed integer, equals or is less than max_int and equals or is greater than min_int.
  """
  defmacro is_int64(value) do
    quote do
    	is_integer(unquote(value))
    	and unquote(value) <= unquote(Asm.max_int)
    	and unquote(value) >= unquote(Asm.min_int)
    end
  end

  @doc """
  is_uint64(value) returns true if the value is an unsigned integer, equals or is less than max_uint and equals or is greater than min_uint.
  """
  defmacro is_uint64(value) do
    quote do
      is_integer(unquote(value))
      and unquote(value) <= unquote(Asm.max_uint)
      and unquote(value) >= unquote(Asm.min_uint)
    end
  end

  @doc """
  is_bignum(value) returns true if the value is an integer but larger than max_uint and smaller than min_int.
  """
  defmacro is_bignum(value) do
    quote do
      is_integer(unquote(value))
      and (unquote(value) > unquote(Asm.max_uint)
      or unquote(value) < unquote(Asm.min_int))
    end
  end

  def dummy(a), do: a
end