Quote range operator atom

This commit has only the actual changes
Add tests for quoted range operator

Author: eksperimental

lib/elixir/lib/code/formatter.ex

@@ -553,6 +553,10 @@ defmodule Code.Formatter do
       if keyword_key?(left_arg) do
         {left, state} =
           case left_arg do
+            # TODO: Remove this clause in v1.16 when we no longer quote operator :..//
+            {:__block__, _, [:"..//"]} ->
+              {string(~S{"..//":}), state}
+
             {:__block__, _, [atom]} when is_atom(atom) ->
               key =
                 case Code.Identifier.classify(atom) do
@@ -1533,6 +1537,11 @@ defmodule Code.Formatter do
     Atom.to_string(atom)
   end
 
+  # TODO: Remove this clause in v1.16 when we no longer quote operator :..//
+  defp atom_to_algebra(:"..//") do
+    string(":\"..//\"")
+  end
+
   defp atom_to_algebra(atom) do
     string = Atom.to_string(atom)
 

lib/elixir/test/elixir/code_formatter/literals_test.exs

@@ -107,6 +107,14 @@ defmodule Code.Formatter.LiteralsTest do
       assert_format ~S[:"++"], ~S[:++]
     end
 
+    test "quoted operators" do
+      assert_same ~S[:"::"]
+      assert_same ~S[:"..//"]
+      assert_format ~S[:..//], ~S[:"..//"]
+      assert_format ~S{[..//: 1]}, ~S{["..//": 1]}
+      assert_same ~S{["..//": 1]}
+    end
+
     test "uses double quotes even when single quotes are used" do
       assert_format ~S[:'foo bar'], ~S[:"foo bar"]
     end