Add unquote: true support to Macro.escape

Author: José Valim

lib/elixir/lib/kernel.ex

@@ -3284,7 +3284,7 @@ defmodule Kernel do
   """
   defmacro defdelegate(funs, opts) do
     quote do
-      funs = unquote(Macro.escape_quoted(funs))
+      funs = unquote(Macro.escape(funs, unquote: true))
       opts = unquote(opts)
 
       target = Keyword.get(opts, :to) ||

lib/elixir/lib/macro.ex

@@ -54,6 +54,10 @@ defmodule Macro do
   Recursively escapes a value so it can be inserted
   into a syntax tree.
 
+  One may pass `unquote: true` to `Macro.escape/2`
+  which leaves unquote statements unescaped, effectively
+  unquoting the contents on escape.
+
   ## Examples
 
       iex> Macro.escape(:foo)
@@ -62,14 +66,12 @@ defmodule Macro do
       iex> Macro.escape({ :a, :b, :c })
       { :{}, [], [:a, :b, :c] }
 
-  """
-  def escape(expr) do
-    :elixir_quote.escape(expr, false) |> elem(0)
-  end
+      iex> Macro.escape({ :unquote, [], [1] }, unquote: true)
+      1
 
-  @doc false
-  def escape_quoted(expr) do
-    :elixir_quote.escape(expr, true) |> elem(0)
+  """
+  def escape(expr, opts // []) do
+    :elixir_quote.escape(expr, Keyword.get(opts, :unquote, false)) |> elem(0)
   end
 
   @doc %B"""

lib/elixir/test/elixir/macro_test.exs

@@ -38,14 +38,14 @@ defmodule MacroTest do
 
   test :escape_with_unquote do
     contents = quote unquote: false, do: unquote(1)
-    assert Macro.escape_quoted(contents) == 1
+    assert Macro.escape(contents, unquote: true) == 1
 
     contents = quote unquote: false, do: unquote(x)
-    assert Macro.escape_quoted(contents) == { :x, [], MacroTest }
+    assert Macro.escape(contents, unquote: true) == { :x, [], MacroTest }
   end
 
   defp eval_escaped(contents) do
-    { eval, [] } = Code.eval_quoted(Macro.escape_quoted(contents))
+    { eval, [] } = Code.eval_quoted(Macro.escape(contents, unquote: true))
     eval
   end
 
@@ -71,7 +71,7 @@ defmodule MacroTest do
 
   test :escape_with_splicing do
     contents = quote unquote: false, do: [1, 2, 3, 4, 5]
-    assert Macro.escape_quoted(contents) == [1, 2, 3, 4, 5]
+    assert Macro.escape(contents, unquote: true) == [1, 2, 3, 4, 5]
 
     contents = quote unquote: false, do: [1, 2, unquote_splicing([3, 4, 5])]
     assert eval_escaped(contents) == [1, 2, 3, 4, 5]

lib/ex_unit/lib/ex_unit/callbacks.ex

@@ -182,7 +182,7 @@ defmodule ExUnit.Callbacks do
   end
 
   defp escape(contents) do
-    Macro.escape_quoted(contents)
+    Macro.escape(contents, unquote: true)
   end
 
   defp compile_callbacks(env, kind) do

lib/ex_unit/lib/ex_unit/case.ex

@@ -92,7 +92,7 @@ defmodule ExUnit.Case do
       end
 
       def message, [unquote(Macro.escape var)], [], do:
-        unquote(Macro.escape_quoted contents)
+        unquote(Macro.escape contents, unquote: true)
     end
   end
 end