Remove Range.empty?/1

Author: josevalim

CHANGELOG.md

@@ -84,7 +84,7 @@ As of Elixir v1.12, implicitly decreasing ranges are soft-deprecated and warning
 
 ## Additional functions
 
-Elixir v1.12 has the additional of many functions across the standard library. The `Enum` module received additions such as `Enum.count_until/2`, `Enum.product/1`, `Enum.zip_with/2`, and more. The `Integer` module now includes `Integer.pow/2` and `Integer.extended_gcd/2`. The `Range` module now deals with stepped ranges and includes new convenience functions such as `Range.empty?/1` and `Range.size/1`. Finally, the `Kernel` module got two new functions, `Kernel.then/2` and `Kernel.tap/2`, which are specially useful in `|>` pipelines.
+Elixir v1.12 has the additional of many functions across the standard library. The `Enum` module received additions such as `Enum.count_until/2`, `Enum.product/1`, `Enum.zip_with/2`, and more. The `Integer` module now includes `Integer.pow/2` and `Integer.extended_gcd/2`. Finally, the `Kernel` module got two new functions, `Kernel.then/2` and `Kernel.tap/2`, which are specially useful in `|>` pipelines.
 
 ## v1.12.0-dev
 
@@ -123,7 +123,7 @@ Elixir v1.12 has the additional of many functions across the standard library. T
   * [Module] Add `Module.get_definition/2` and `Module.delete_definition/2`
   * [Module] Allow `@on_load` to be a private function
   * [Module] Validate `@dialyzer` related module attributes
-  * [Range] Add `Range.new/3`, `Range.empty?/1`, and `Range.size/1`
+  * [Range] Add `Range.new/3` and `Range.size/1`
   * [Regex] Add offset option to `Regex.scan/3` and `Regex.run/3`
   * [Registry] Support `:compression` on `Registry` tables
   * [Stream] Add `Stream.zip_with/2` and `Stream.zip_with/3`

lib/elixir/lib/enum.ex

@@ -2026,11 +2026,13 @@ defmodule Enum do
   def min_max(enumerable, empty_fallback \\ fn -> raise Enum.EmptyError end)
 
   def min_max(first..last//step = range, empty_fallback) when is_function(empty_fallback, 0) do
-    if Range.empty?(range) do
-      empty_fallback.()
-    else
-      last = last - rem(last - first, step)
-      {Kernel.min(first, last), Kernel.max(first, last)}
+    case Range.size(range) do
+      0 ->
+        empty_fallback.()
+
+      _ ->
+        last = last - rem(last - first, step)
+        {Kernel.min(first, last), Kernel.max(first, last)}
     end
   end
 
@@ -3611,15 +3613,17 @@ defmodule Enum do
   end
 
   defp aggregate(first..last//step = range, fun, empty) do
-    if Range.empty?(range) do
-      empty.()
-    else
-      last = last - rem(last - first, step)
+    case Range.size(range) do
+      0 ->
+        empty.()
 
-      case fun.(first, last) do
-        true -> first
-        false -> last
-      end
+      _ ->
+        last = last - rem(last - first, step)
+
+        case fun.(first, last) do
+          true -> first
+          false -> last
+        end
     end
   end
 

lib/elixir/lib/range.ex

@@ -150,26 +150,6 @@ defmodule Range do
             "non-zero integer, got: #{inspect(first)}..#{inspect(last)}//#{inspect(step)}"
   end
 
-  @doc """
-  Checks if the range is empty.
-
-  ## Examples
-
-      iex> Range.empty?(1..0//1)
-      true
-      iex> Range.empty?(0..1//-1)
-      true
-      iex> Range.empty?(1..0)
-      false
-      iex> Range.empty?(0..1)
-      false
-
-  """
-  @doc since: "1.12.0"
-  def empty?(first..last//step) when step > 0 and first > last, do: true
-  def empty?(first..last//step) when step < 0 and first < last, do: true
-  def empty?(_.._//_), do: false
-
   @doc """
   Returns the size of the range.
 
@@ -242,7 +222,7 @@ defmodule Range do
   @doc since: "1.8.0"
   @spec disjoint?(t, t) :: boolean
   def disjoint?(first1..last1//step1 = range1, first2..last2//step2 = range2) do
-    if empty?(range1) or empty?(range2) do
+    if size(range1) == 0 or size(range2) == 0 do
       true
     else
       {first1, last1, step1} = normalize(first1, last1, step1)
@@ -273,7 +253,7 @@ defmodule Range do
     end
   end
 
-  @compile inline: [normalize: 3, empty?: 1]
+  @compile inline: [normalize: 3]
   defp normalize(first, last, step) when first > last, do: {last, first, -step}
   defp normalize(first, last, step), do: {first, last, step}
 
@@ -309,7 +289,7 @@ defimpl Enumerable, for: Range do
 
   def member?(first..last//step = range, value) when is_integer(value) do
     cond do
-      Range.empty?(range) ->
+      Range.size(range) == 0 ->
         {:ok, false}
 
       first <= last ->