Document inlined functions are BIFs

Author: José Valim

lib/elixir/lib/kernel.ex

@@ -20,8 +20,13 @@ defmodule Kernel do
 
   Some of the functions described in this module are inlined by
   the Elixir compiler into their Erlang counterparts in the `:erlang`
-  module. You can usually see this in effect when capturing the
-  function:
+  module. Those functions are called BIFs (builtin internal functions)
+  in Erlang-land and they exhibit interesting properties, as some of
+  them are allowed in guards and others are used for compiler
+  optimizations.
+
+  Most of the inlined functions can be seen in effect when capturing
+  the function:
 
       iex> &Kernel.is_atom/1
       &:erlang.is_atom/1

lib/elixir/lib/node.ex

@@ -3,8 +3,9 @@ defmodule Node do
   Functions related to VM nodes.
 
   Some of the functions in this module are inlined by the compiler,
-  similar to functions in the `Kernel` module. When such happens,
-  they are explicitly tagged as so.
+  similar to functions in the `Kernel` module and they are explicitly
+  marked in their docs as "inlined by the compiler". For more information
+  about inlined functions, check out the `Kernel` module.
   """
 
   @type t :: atom

lib/elixir/lib/process.ex

@@ -3,8 +3,9 @@ defmodule Process do
   Conveniences for working with processes and the process dictionary.
 
   Some of the functions in this module are inlined by the compiler,
-  similar to functions in the `Kernel` module. When such happens,
-  they are explicitly tagged as so.
+  similar to functions in the `Kernel` module and they are explicitly
+  marked in their docs as "inlined by the compiler". For more information
+  about inlined functions, check out the `Kernel` module.
   """
 
   @doc """

lib/elixir/src/elixir_dispatch.erl

@@ -20,7 +20,7 @@ default_functions() ->
 default_macros() ->
   [ { ?kernel, elixir_imported_macros() } ].
 default_requires() ->
-  [ 'Elixir.Integer', 'Elixir.Kernel', 'Elixir.Kernel.Typespec', 'Elixir.Record' ].
+  [ 'Elixir.Kernel', 'Elixir.Kernel.Typespec', 'Elixir.Record' ].
 
 find_import(Meta, Name, Arity, E) ->
   Tuple = { Name, Arity },

lib/elixir/test/elixir/integer_test.exs

@@ -2,8 +2,10 @@ Code.require_file "test_helper.exs", __DIR__
 
 defmodule IntegerTest do
   use ExUnit.Case, async: true
+  require Integer
 
   test :odd? do
+    assert Integer.odd?(0) == false
     assert Integer.odd?(1) == true
     assert Integer.odd?(2) == false
     assert Integer.odd?(3) == true
@@ -13,6 +15,7 @@ defmodule IntegerTest do
   end
 
   test :even? do
+    assert Integer.even?(0) == true
     assert Integer.even?(1) == false
     assert Integer.even?(2) == true
     assert Integer.even?(3) == false