     map(collection, fn(x) -> x end)
   end
 
-  # Returns if the collection is empty or not.
-  #
-  # ## Examples
-  #
-  #     Enum.empty? [] #=> true
-  #     Enum.empty? [1,2,3] #=> false
-  #
+  @doc """
+  Returns if the collection is empty or not.
+
+  ## Examples
+
+      Enum.empty? [] #=> true
+      Enum.empty? [1,2,3] #=> false
+
+  """
   def empty?(collection) when is_list(collection) do
     collection == []
   end

    pointer
  end

  # Returns all the entries in the collection. It is the equivalent
  # to calling map with an identify function.
  #
  # ## Examples
  #
  #     Enum.entries [1,2,3] #=> [1,2,3]
  #
  def entries(collection) when is_list(collection) do
    collection
  end

    do_keyfind(pointer, iterator, key, position, default)
  end

  @doc """
  Invokes the given `fun` for each item in the `collection`.
    Returns the result of all function calls.

    ## Examples

        Enum.map [1, 2, 3], fn(x, do: x * 2)
        #=> [2, 4, 6]

  """
  def map(collection, fun) when is_list(collection) do
    lc item in collection, do: fun.(item)
  end
