Add some handy-dandy number formatting.

lib/wafer/format.ex

@@ -0,0 +1,67 @@
+defmodule Wafer.Format do
+  use Bitwise
+
+  @moduledoc """
+  Handy functions for formatting bytes, especially for debugging.
+  """
+
+  @doc """
+  Convert the provided value into it's 0-padded byte-oriented string
+  representation.
+
+  ## Examples
+
+      iex> to_hex(0x1234)
+      "0x1234"
+
+      iex> to_hex(<<0xF0, 0x0F>>)
+      "0xF00F"
+  """
+  @spec to_hex(integer | binary) :: String.t()
+  def to_hex(value) when is_integer(value) do
+    value
+    |> :binary.encode_unsigned()
+    |> to_hex()
+  end
+
+  def to_hex(value) when is_binary(value) do
+    bits =
+      value
+      |> :binary.bin_to_list()
+      |> Stream.map(&Integer.to_string(&1, 16))
+      |> Stream.map(&String.pad_leading(&1, 2, "0"))
+      |> Enum.join("")
+
+    "0x" <> bits
+  end
+
+  @doc """
+  Convert the provided value into it's 0-padded byte-oriented string
+  representation.
+
+  ## Examples
+
+      iex> to_bin(0x1234)
+      "0b00010010_00110100"
+
+      iex> to_bin(<<0xF0, 0x0F>>)
+      "0b11110000_00001111"
+  """
+  @spec to_bin(integer | binary) :: String.t()
+  def to_bin(value) when is_integer(value) do
+    value
+    |> :binary.encode_unsigned()
+    |> to_bin()
+  end
+
+  def to_bin(value) when is_binary(value) do
+    bits =
+      value
+      |> :binary.bin_to_list()
+      |> Stream.map(&Integer.to_string(&1, 2))
+      |> Stream.map(&String.pad_leading(&1, 8, "0"))
+      |> Enum.join("_")
+
+    "0b" <> bits
+  end
+end

test/format_test.exs

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+defmodule WaferFormatTest do
+  use ExUnit.Case, async: true
+  import Wafer.Format
+  doctest Wafer.Format
+end