Remove improper_list/2

Author: sabiwara

lib/elixir/lib/module/types/descr.ex

@@ -76,9 +76,6 @@ defmodule Module.Types.Descr do
   def list(type), do: list_descr(type, @empty_list, true)
   def non_empty_list(type), do: list_descr(type, @empty_list, false)
   def non_empty_maybe_improper_list(type, tail), do: list_descr(type, tail, false)
-  def improper_list(), do: improper_list(term(), term())
-  def improper_list(type, :term), do: list_descr(type, @not_list, false)
-  def improper_list(type, tail), do: list_descr(type, difference(tail, list(term())), false)
   def open_map(), do: %{map: @map_top}
   def open_map(pairs), do: map_descr(:open, pairs)
   def open_tuple(elements, _fallback \\ term()), do: tuple_descr(:open, elements)

lib/elixir/test/elixir/module/types/descr_test.exs

@@ -1336,23 +1336,30 @@ defmodule Module.Types.DescrTest do
       assert list(term(), term()) |> to_quoted_string() ==
                "empty_list() or non_empty_maybe_improper_list(term(), term())"
 
-      assert improper_list(term(), term()) |> to_quoted_string() ==
-               "improper_list(term(), term())"
+      assert non_empty_maybe_improper_list(term(), term()) |> to_quoted_string() ==
+               "non_empty_maybe_improper_list(term(), term())"
 
-      assert improper_list(integer(), integer()) |> to_quoted_string() ==
-               "improper_list(integer(), integer())"
+      assert non_empty_maybe_improper_list(term(), difference(term(), empty_list()))
+             |> to_quoted_string() ==
+               "non_empty_maybe_improper_list(term(), term())"
+
+      assert non_empty_maybe_improper_list(integer(), integer()) |> to_quoted_string() ==
+               "non_empty_maybe_improper_list(integer(), integer())"
 
-      assert union(empty_list(), improper_list(integer(), integer())) |> to_quoted_string() ==
-               "empty_list() or improper_list(integer(), integer())"
+      assert union(empty_list(), non_empty_maybe_improper_list(integer(), integer()))
+             |> to_quoted_string() ==
+               "empty_list() or non_empty_maybe_improper_list(integer(), integer())"
 
-      assert union(non_empty_list(integer()), improper_list(integer(), integer()))
+      assert union(non_empty_list(integer()), non_empty_maybe_improper_list(integer(), integer()))
              |> to_quoted_string() ==
                "non_empty_maybe_improper_list(integer(), empty_list() or integer())"
 
-      assert union(list(integer()), improper_list(integer(), integer())) |> to_quoted_string() ==
+      assert union(list(integer()), non_empty_maybe_improper_list(integer(), integer()))
+             |> to_quoted_string() ==
                "empty_list() or non_empty_maybe_improper_list(integer(), empty_list() or integer())"
 
-      assert union(list(term()), improper_list(term(), term())) |> to_quoted_string() ==
+      assert union(list(term()), non_empty_maybe_improper_list(term(), term()))
+             |> to_quoted_string() ==
                "empty_list() or non_empty_maybe_improper_list(term(), term())"
 
       # Test normalization