Document dedup uses ===, remove usort

5 files changed, 8 insertions, 58 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4f1a6b1f8..d8564fe8d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -42,7 +42,7 @@ and is using Erlang 17.1, remember to update to at least Erlang 17.3.
   * [Dict] Add `Dict.get_and_update/3` which behaves similar to the now deprecated Access protocol
   * [Dict] Add `Dict.get_lazy/3`, `Dict.pop_lazy/3` and `Dict.put_new_lazy/3`
   * [EEx] Add `:trim` option to EEx that automatically trims the left side of `<%` and right side `%>` if only spaces and new lines preceed/follow them
-  * [Enum] Add `Enum.random/1`, `Enum.minmax/1`, `Enum.minmax_by/2`, `Enum.reverse_slice/3`, `Enum.dedup/1`, `Enum.dedup_by/2`, `Enum.usort/1` and `Enum.usort_by/2`
+  * [Enum] Add `Enum.random/1`, `Enum.minmax/1`, `Enum.minmax_by/2`, `Enum.reverse_slice/3`, `Enum.dedup/1` and `Enum.dedup_by/2`
   * [Enum] Inline common map usage in `Enum` functions for performance
   * [ExUnit] Add number of skipped tests to `ExUnit` output
   * [ExUnit] Make timeout configurable for the whole test suite via the `:timeout` configuration
@@ -61,7 +61,7 @@ and is using Erlang 17.1, remember to update to at least Erlang 17.3.
   * [Mix] Allow rebar dependencies to be specified via `:path`
   * [Record] Expand attributes and macros when extracting records
   * [Set] Introduce `MapSet` data type. This new data type uses maps behind the scenes and is useful for storing a dozens of items in Erlang 17. In future versions when maps efficiently support large collections, it is meant to be the main Set abstraction in Elixir
-  * [Stream] Add `Stream.dedup/1`, `Stream.dedup_by/2`, `Stream.usort/1` and `Stream.usort_by/2`
+  * [Stream] Add `Stream.dedup/1` and `Stream.dedup_by/2`
   * [String] Support calculation of the jaro distance between strings (usually names) via `String.jaro_distance/2`. This is used by Mix to support "Did you mean?" feature when a task does not exist
   * [StringIO] `StringIO.flush/1` was added to flush the output of a StringIO device
   * [URI] Default ports were added for "ws" and "wss" schemas
diff --git a/lib/elixir/lib/enum.ex b/lib/elixir/lib/enum.ex
index 0ff96d110..f759e203b 100644
--- a/lib/elixir/lib/enum.ex
+++ b/lib/elixir/lib/enum.ex
@@ -466,6 +466,8 @@ defmodule Enum do
   Enumerates the collection, returning a list where all consecutive
   duplicated elements are collapsed to a single element.
 
+  Elements are compared using `===`.
+
   ## Examples
 
       iex> Enum.dedup([1, 2, 3, 3, 2, 1])
@@ -2101,44 +2103,6 @@ defmodule Enum do
   end
 
   @doc """
-  Sorts the collection, eliminating duplicate elements (one element is kept
-  from each group of duplicates).
-
-  ## Examples
-
-      iex> Enum.usort([5, 1, 2, 3, 2, 1])
-      [1, 2, 3, 5]
-
-  """
-  @spec usort(t) :: list
-  def usort(collection) when is_list(collection) do
-    :lists.usort(collection)
-  end
-
-  def usort(collection) do
-    collection |> sort |> dedup
-  end
-
-  @doc """
-  Sorts the collection, eliminating duplicate elements (one element is kept
-  from each group of duplicates).
-
-  The function `fun` maps every element to a term which is used to
-  sort and dedup by.
-
-  ## Examples
-
-      iex> Enum.usort_by([5, 1, 2, 3, 2, 1], fn x -> x > 2 end)
-      [1, 5]
-
-  """
-
-  @spec usort_by(t, (element -> term)) :: list
-  def usort_by(collection, fun) do
-    collection |> sort_by(fun) |> dedup_by(fun)
-  end
-
-  @doc """
   Opposite of `Enum.zip/2`; takes a list of two-element tuples and returns a
   tuple with two lists, each of which is formed by the first and second element
   of each tuple, respectively.
diff --git a/lib/elixir/lib/stream.ex b/lib/elixir/lib/stream.ex
index 1a3f55b7d..2d14a14e4 100644
--- a/lib/elixir/lib/stream.ex
+++ b/lib/elixir/lib/stream.ex
@@ -211,6 +211,8 @@ defmodule Stream do
 
   This function only ever needs to store the last emitted element.
 
+  Elements are compared using `===`.
+
   ## Examples
 
       iex> Stream.dedup([1, 2, 3, 3, 2, 1]) |> Enum.to_list
diff --git a/lib/elixir/test/elixir/enum_test.exs b/lib/elixir/test/elixir/enum_test.exs
index 46f33ba94..6830a698c 100644
--- a/lib/elixir/test/elixir/enum_test.exs
+++ b/lib/elixir/test/elixir/enum_test.exs
@@ -98,6 +98,7 @@ defmodule EnumTest.List do
     assert Enum.dedup([1, 1, 2, 1, 1, 2, 1]) == [1, 2, 1, 2, 1]
     assert Enum.dedup([2, 1, 1, 2, 1]) == [2, 1, 2, 1]
     assert Enum.dedup([1, 2, 3, 4]) == [1, 2, 3, 4]
+    assert Enum.dedup([1, 1.0, 2.0, 2]) == [1, 1.0, 2.0, 2]
     assert Enum.dedup([]) == []
     assert Enum.dedup([nil, nil, true, {:value, true}]) == [nil, true, {:value, true}]
     assert Enum.dedup([nil]) == [nil]
@@ -458,14 +459,6 @@ defmodule EnumTest.List do
     assert Enum.uniq([1, 2, 3, 2, 1], fn x -> x end) == [1, 2, 3]
   end
 
-  test :usort do
-    assert Enum.usort([5, 1, 2, 3, 2, 1]) == [1, 2, 3, 5]
-  end
-
-  test :usort_by do
-    assert Enum.usort_by([5, 1, 2, 3, 2, 1], fn x -> x > 2 end) == [1, 5]
-  end
-
   test :zip do
     assert Enum.zip([:a, :b], [1, 2]) == [{:a, 1}, {:b, 2}]
     assert Enum.zip([:a, :b], [1, 2, 3, 4]) == [{:a, 1}, {:b, 2}]
@@ -1111,16 +1104,6 @@ defmodule EnumTest.Range do
     assert Enum.uniq(1..3, fn x -> x end) == [1, 2, 3]
   end
 
-  test :usort do
-    assert Enum.usort(1..3) == [1, 2, 3]
-    assert Stream.cycle(3..1) |> Stream.take(10) |> Enum.usort == [1, 2, 3]
-  end
-
-  test :usort_by do
-    assert Enum.usort_by(1..3, fn x -> x > 1 end) == [1, 2]
-    assert Stream.cycle(3..1) |> Stream.take(10) |> Enum.usort_by(fn x -> x > 1 end) == [1, 3]
-  end
-
   test :zip do
     assert Enum.zip([:a, :b], 1..2) == [{:a, 1}, {:b, 2}]
     assert Enum.zip([:a, :b], 1..4) == [{:a, 1}, {:b, 2}]
diff --git a/lib/elixir/test/elixir/stream_test.exs b/lib/elixir/test/elixir/stream_test.exs
index fc57757a4..dc7ac1ce8 100644
--- a/lib/elixir/test/elixir/stream_test.exs
+++ b/lib/elixir/test/elixir/stream_test.exs
@@ -163,6 +163,7 @@ defmodule StreamTest do
     assert Stream.dedup([1, 1, 2, 1, 1, 2, 1]) |> Enum.to_list == [1, 2, 1, 2, 1]
     assert Stream.dedup([2, 1, 1, 2, 1]) |> Enum.to_list  == [2, 1, 2, 1]
     assert Stream.dedup([1, 2, 3, 4]) |> Enum.to_list  == [1, 2, 3, 4]
+    assert Stream.dedup([1, 1.0, 2.0, 2]) |> Enum.to_list  == [1, 1.0, 2.0, 2]
     assert Stream.dedup([]) |> Enum.to_list  == []
     assert Stream.dedup([nil, nil, true, {:value, true}]) |> Enum.to_list
       == [nil, true, {:value, true}]