Merge pull request #2511 from ericmj/macro-tostring-sigils

Use sigil syntax in Macro.to_string

Author: ericmj

lib/elixir/lib/macro.ex

@@ -525,11 +525,15 @@ defmodule Macro do
 
   # All other calls
   def to_string({target, _, args} = ast, fun) when is_list(args) do
-    {list, last} = :elixir_utils.split_last(args)
-    fun.(ast, case kw_blocks?(last) do
-      true  -> call_to_string_with_args(target, list, fun) <> kw_blocks_to_string(last, fun)
-      false -> call_to_string_with_args(target, args, fun)
-    end)
+    if sigil = sigil_call(ast, fun) do
+      sigil
+    else
+      {list, last} = :elixir_utils.split_last(args)
+      fun.(ast, case kw_blocks?(last) do
+        true  -> call_to_string_with_args(target, list, fun) <> kw_blocks_to_string(last, fun)
+        false -> call_to_string_with_args(target, args, fun)
+      end)
+    end
   end
 
   # Two-item tuples
@@ -565,6 +569,26 @@ defmodule Macro do
   defp module_to_string(atom, _fun) when is_atom(atom), do: inspect(atom, [])
   defp module_to_string(other, fun), do: call_to_string(other, fun)
 
+  defp sigil_call({func, _, [{:<<>>, _, [string]}, args]} = ast, fun) when is_list(args) do
+    sigil =
+      case Atom.to_string(func) do
+        <<"sigil_", name>> ->
+          "~" <> <<name>> <>
+          fun.(string, inspect(string, [])) <>
+          sigil_args(args, fun)
+        _ ->
+          nil
+      end
+    fun.(ast, sigil)
+  end
+
+  defp sigil_call(_other, _fun) do
+    nil
+  end
+
+  defp sigil_args([], _fun),   do: ""
+  defp sigil_args(args, fun), do: fun.(args, List.to_string(args))
+
   defp call_to_string(atom, _fun) when is_atom(atom), do: Atom.to_string(atom)
   defp call_to_string({:., _, [arg]}, fun),           do: module_to_string(arg, fun) <> "."
   defp call_to_string({:., _, [left, right]}, fun),   do: module_to_string(left, fun) <> "." <> call_to_string(right, fun)

lib/elixir/test/elixir/macro_test.exs

@@ -275,6 +275,16 @@ defmodule MacroTest do
     assert Macro.to_string(quote do: Foo.Bar.baz([1, 2, 3])) == "Foo.Bar.baz([1, 2, 3])"
   end
 
+  test :sigil_call_to_string do
+    assert Macro.to_string(quote do: ~r"123") == ~s/~r"123"/
+    assert Macro.to_string(quote do: ~r"123"u) == ~s/~r"123"u/
+    assert Macro.to_string(quote do: ~r"\n123") == ~s/~r"\\\\n123"/
+
+    assert Macro.to_string(quote do: ~R"123") == ~s/~R"123"/
+    assert Macro.to_string(quote do: ~R"123"u) == ~s/~R"123"u/
+    assert Macro.to_string(quote do: ~R"\n123") == ~s/~R"\\\\n123"/
+  end
+
   test :arrow_to_string do
     assert Macro.to_string(quote do: foo(1, (2 -> 3))) == "foo(1, (2 -> 3))"
   end