Add pending deprecation

Author: josevalim

lib/nimble_parsec/compiler.ex

@@ -430,7 +430,7 @@ defmodule NimbleParsec.Compiler do
 
       {acc, context} when acc != :error ->
         IO.warn(
-          "Returning a two-element tuple {acc, context} in pre_traverse/post_traverse is deprecated, " <>
+          "returning a two-element tuple {acc, context} in pre_traverse/post_traverse is deprecated, " <>
             "please return {rest, acc, context} instead"
         )
 
@@ -443,9 +443,19 @@ defmodule NimbleParsec.Compiler do
         # TODO: Deprecate two element tuple return that is not error
         quote generated: true do
           case unquote(quoted) do
-            {_, _, _} = res -> res
-            {:error, reason} -> {:error, reason}
-            {acc, context} -> {unquote(rest), acc, context}
+            {_, _, _} = res ->
+              res
+
+            {:error, reason} ->
+              {:error, reason}
+
+            {acc, context} ->
+              IO.warn(
+                "returning a two-element tuple {acc, context} in pre_traverse/post_traverse is deprecated, " <>
+                  "please return {rest, acc, context} instead"
+              )
+
+              {unquote(rest), acc, context}
           end
         end
     end

test/integration_test.exs

@@ -69,12 +69,12 @@ defmodule NimbleParsec.IntegrationTest do
               |> post_traverse({:sign_int_value, []})
               |> tag(:signed_int)
 
-    defp sign_int_value(_rest, [int, _neg], context, _, _) do
-      {[int * -1], context}
+    defp sign_int_value(rest, [int, _neg], context, _, _) do
+      {rest, [int * -1], context}
     end
 
-    defp sign_int_value(_rest, res, context, _, _) do
-      {res, context}
+    defp sign_int_value(rest, res, context, _, _) do
+      {rest, res, context}
     end
 
     test "returns ok/error" do
@@ -90,8 +90,8 @@ defmodule NimbleParsec.IntegrationTest do
 
     defparsec :language_code, language_code
 
-    defp atomize_language_code(_rest, [language_code], context, _line, _offset) do
-      {[String.to_atom(language_code)], context}
+    defp atomize_language_code(rest, [language_code], context, _line, _offset) do
+      {rest, [String.to_atom(language_code)], context}
     end
 
     test "returns ok/error" do

test/nimble_parsec_test.exs

@@ -1500,8 +1500,8 @@ defmodule NimbleParsecTest do
     end
   end
 
-  defp location(_rest, args, %{} = context, line, offset, tag) do
-    {[{tag, args, line, offset}], context}
+  defp location(rest, args, %{} = context, line, offset, tag) do
+    {rest, [{tag, args, line, offset}], context}
   end
 
   defp bound?(document) do
@@ -1554,6 +1554,6 @@ defmodule NimbleParsecTest do
   defp private_join_and_wrap(rest, args, %{} = context, {line, line_offset}, byte_offset, joiner)
        when is_binary(rest) and is_integer(line) and is_integer(line_offset) and
               is_integer(byte_offset) do
-    {args |> Enum.join(joiner) |> List.wrap(), context}
+    {rest, args |> Enum.join(joiner) |> List.wrap(), context}
   end
 end