From 9f4752a8f8add35acf8685ef70677178409ce76c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Valim?= <jose.valim@dashbit.co>
Date: Sat, 12 Feb 2022 11:28:56 +0100
Subject: [PATCH] Use three element tuples for strings and integers

---
 lib/nimble_parsec.ex          | 24 ++++++++++++------------
 lib/nimble_parsec/compiler.ex |  7 ++++++-
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/lib/nimble_parsec.ex b/lib/nimble_parsec.ex
index 3ab9940..0bfa065 100644
--- a/lib/nimble_parsec.ex
+++ b/lib/nimble_parsec.ex
@@ -1979,28 +1979,28 @@ defmodule NimbleParsec do
   end
 
   @doc false
-  def __runtime_string__(_rest, acc, context, _line, _offset, _min, _max, _type) do
+  def __runtime_string__(rest, acc, context, _line, _offset, _min, _max, _type) do
     ast = quote(do: List.to_string(unquote(reverse_now_or_later(acc))))
-    {[ast], context}
+    {:{}, [], [rest, [ast], context]}
   end
 
   @doc false
-  def __compile_string__(_rest, acc, context, _line, _offset, _count, type) when is_list(acc) do
+  def __compile_string__(rest, acc, context, _line, _offset, _count, type) when is_list(acc) do
     acc =
       for entry <- :lists.reverse(acc) do
         {:"::", [], [entry, type]}
       end
 
-    {[{:<<>>, [], acc}], context}
+    {:{}, [], [rest, [{:<<>>, [], acc}], context]}
   end
 
-  def __compile_string__(_rest, acc, context, _line, _offset, _count, _type) do
+  def __compile_string__(rest, acc, context, _line, _offset, _count, _type) do
     ast = quote(do: List.to_string(unquote(reverse_now_or_later(acc))))
-    {[ast], context}
+    {:{}, [], [rest, [ast], context]}
   end
 
   @doc false
-  def __runtime_integer__(_rest, acc, context, _line, _offset, min, _max)
+  def __runtime_integer__(rest, acc, context, _line, _offset, min, _max)
       when is_integer(min) and min > 0 do
     ast =
       quote do
@@ -2008,27 +2008,27 @@ defmodule NimbleParsec do
         [:lists.foldl(fn x, acc -> x - ?0 + acc * 10 end, head, tail)]
       end
 
-    {ast, context}
+    {:{}, [], [rest, ast, context]}
   end
 
-  def __runtime_integer__(_rest, acc, context, _line, _offset, _min, _max) do
+  def __runtime_integer__(rest, acc, context, _line, _offset, _min, _max) do
     ast =
       quote do
         [head | tail] = unquote(reverse_now_or_later(acc))
         [:lists.foldl(fn x, acc -> x - ?0 + acc * 10 end, head - ?0, tail)]
       end
 
-    {ast, context}
+    {:{}, [], [rest, ast, context]}
   end
 
   @doc false
-  def __compile_integer__(_rest, acc, context, _line, _offset, _count) when is_list(acc) do
+  def __compile_integer__(rest, acc, context, _line, _offset, _count) when is_list(acc) do
     ast =
       acc
       |> quoted_ascii_to_integer(1)
       |> Enum.reduce(&{:+, [], [&2, &1]})
 
-    {[ast], context}
+    {:{}, [], [rest, [ast], context]}
   end
 
   defp reverse_now_or_later(list) when is_list(list), do: :lists.reverse(list)
diff --git a/lib/nimble_parsec/compiler.ex b/lib/nimble_parsec/compiler.ex
index b2231e2..48d51fb 100644
--- a/lib/nimble_parsec/compiler.ex
+++ b/lib/nimble_parsec/compiler.ex
@@ -417,19 +417,24 @@ defmodule NimbleParsec.Compiler do
     end
   end
 
-  # TODO: Deprecate two element tuple return that is not error
   defp apply_traverse_mfa(mfargs, args, rest) do
     case apply_mfa(mfargs, args) do
       {:{}, _, [_, _, _]} = res ->
         res
 
       {acc, context} when acc != :error ->
+        # IO.warn(
+        #   "Returning a two-element tuple {acc, context} in pre_traverse/post_traverse is deprecated, " <>
+        #     "please return {rest, acc, context} instead"
+        # )
+
         {:{}, [], [rest, acc, context]}
 
       {:error, context} ->
         {:error, context}
 
       quoted ->
+        # TODO: Deprecate two element tuple return that is not error
         quote generated: true do
           case unquote(quoted) do
             {_, _, _} = res -> res