Deprecate Regex.index/2

Author: José Valim

lib/elixir/lib/regex.ex

@@ -79,20 +79,12 @@ defmodule Regex do
     end
   end
 
-  @doc """
-  Runs the regular expression against the given string
-  and returns the index (zero indexes) where the first
-  match occurs, nil otherwise.
-
-  ## Examples
-
-      iex> Regex.index(%r/c(d)/, "abcd")
-      2
-      iex> Regex.index(%r/e/, "abcd")
-      nil
-
-  """
+  @doc false
   def index(regex(re_pattern: compiled), string) do
+    IO.puts "Regex.index(re, string) is deprecated. Please use " <>
+      "Regex.run(re, string, return: :index) instead."
+    Exception.print_stacktrace
+
     case :re.run(string, compiled, [{ :capture, :first, :index }]) do
       :nomatch -> nil
       { :match, [{index,_}] } -> index
@@ -125,6 +117,8 @@ defmodule Regex do
       ["cd", "d"]
       iex> Regex.run(%r/e/, "abcd")
       nil
+      iex> Regex.run(%r/c(d)/, "abcd", return: :index)
+      [{2,2},{3,1}]
 
   """
   def run(regex, string, options // [])

lib/elixir/test/elixir/regex_test.exs

@@ -93,11 +93,6 @@ defmodule Regex.BinaryTest do
     assert Regex.run(%r"e", "abcd", return: :index) == nil
   end
 
-  test :index do
-    assert Regex.index(%r"c(d)", "abcd") == 2
-    assert Regex.index(%r"e", "abcd") == nil
-  end
-
   test :scan do
     assert Regex.scan(%r"c(d|e)", "abcd abce") == [["d"], ["e"]]
     assert Regex.scan(%r"c(?:d|e)", "abcd abce") == ["cd", "ce"]
@@ -183,11 +178,6 @@ defmodule Regex.ListTest do
     assert Regex.run(%r"c(d)", "abcd", return: :binary) == ["cd", "d"]
   end
 
-  test :index do
-    assert Regex.index(%r'c(d)', 'abcd') == 2
-    assert Regex.index(%r'e', 'abcd') == nil
-  end
-
   test :indexes do
     assert Regex.run(%r'c(d)', 'abcd', return: :index) == [{2,2},{3,1}]
     assert Regex.run(%r'e', 'abcd', return: :index) == nil