       [2, 4, 6, 8]
 
       # A comprehension with two generators
-      iex> for x <- [1, 2], y <- [2, 3], do: x*y
+      iex> for x <- [1, 2], y <- [2, 3], do: x * y
       [2, 3, 4, 6]
 
   Filters can also be given:


      defmodule ImageTyper
        @png_signature <<137::size(8), 80::size(8), 78::size(8), 71::size(8),
                      13::size(8), 10::size(8), 26::size(8), 10::size(8)>>
        @jpg_signature <<255::size(8), 216::size(8)>>

        def type(<<@png_signature, rest::binary>>), do: :png

  need to organize bitstring streams:

      iex> pixels = <<213, 45, 132, 64, 76, 32, 76, 0, 0, 234, 32, 15>>
      iex> for <<r::8, g::8, b::8 <- pixels>>, do: {r, g, b}
      [{213, 45, 132}, {64, 76, 32}, {76, 0, 0}, {234, 32, 15}]

  Variable assignments inside the comprehension, be it in generators,
