Remove deprecated code and add TODOs

Author: josevalim

lib/elixir/lib/code/formatter.ex

@@ -289,6 +289,7 @@ defmodule Code.Formatter do
     end
   end
 
+  # TODO: Remove this clause on Elixir v2.0 once single-quoted charlists are removed
   defp quoted_to_algebra(
          {{:., _, [List, :to_charlist]}, meta, [entries]} = quoted,
          context,
@@ -2224,6 +2225,7 @@ defmodule Code.Formatter do
       (not interpolated?(entries) and eol_or_comments?(meta, state))
   end
 
+  # TODO: Remove this clause on Elixir v2.0 once single-quoted charlists are removed
   defp next_break_fits?({{:., _, [List, :to_charlist]}, meta, [[_ | _]]}, _state) do
     meta[:delimiter] == ~s[''']
   end

lib/elixir/lib/code/normalizer.ex

@@ -96,6 +96,7 @@ defmodule Code.Normalizer do
   end
 
   # Charlists with interpolations
+  # TODO: Remove this clause on Elixir v2.0 once single-quoted charlists are removed
   defp do_normalize({{:., dot_meta, [List, :to_charlist]}, call_meta, [parts]} = quoted, state) do
     if list_interpolated?(parts) do
       parts =

lib/elixir/test/elixir/code_normalizer/quoted_ast_test.exs

@@ -688,28 +688,6 @@ defmodule Code.Normalizer.QuotedASTTest do
       assert quoted_to_string(~c"\x00\x01\x10") == ~S/[0, 1, 16]/
     end
 
-    test "charlists with interpolations" do
-      # using string_to_quoted to avoid the formatter fixing the charlists
-
-      assert Code.string_to_quoted!(~S/'one #{2} three'/) |> quoted_to_string(escape: false) ==
-               ~S/~c"one #{2} three"/
-
-      assert Code.string_to_quoted!(~S/'one #{2} three'/) |> quoted_to_string() ==
-               ~S/~c"one #{2} three"/
-
-      assert Code.string_to_quoted!(~S/'one\n\'#{2}\'\nthree'/) |> quoted_to_string(escape: false) ==
-               ~s[~c"one\n'\#{2}'\nthree"]
-
-      assert Code.string_to_quoted!(~S/'one\n\'#{2}\'\nthree'/) |> quoted_to_string() ==
-               ~S[~c"one\n'#{2}'\nthree"]
-
-      assert Code.string_to_quoted!(~S/'one\n"#{2}"\nthree'/) |> quoted_to_string(escape: false) ==
-               ~s[~c"one\n\\"\#{2}\\"\nthree"]
-
-      assert Code.string_to_quoted!(~S/'one\n"#{2}"\nthree'/) |> quoted_to_string() ==
-               ~S[~c"one\n\"#{2}\"\nthree"]
-    end
-
     test "atoms" do
       assert quoted_to_string(quote(do: :"a\nb\tc"), escape: false) == ~s/:"a\nb\tc"/
       assert quoted_to_string(quote(do: :"a\nb\tc")) == ~S/:"a\nb\tc"/