From e963a934ed2463474dfccf9595c66baac10c25ec Mon Sep 17 00:00:00 2001
From: Tanguy <tanguy@status.im>
Date: Tue, 21 Jun 2022 14:52:46 +0200
Subject: [PATCH] Workaround template & quote do binding issues

---
 questionable/binding.nim | 10 ++++++----
 questionable/results.nim | 19 +++++++++++++------
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/questionable/binding.nim b/questionable/binding.nim
index 5cf91e9..55bf8f0 100644
--- a/questionable/binding.nim
+++ b/questionable/binding.nim
@@ -14,15 +14,17 @@ macro `=?`*(name, expression): bool =
   ## instance in an `if` statement.
 
   name.expectKind({nnkIdent, nnkVarTy})
+
+  # Outside of the quote do to avoid binding symbol too early
+  let unpacker = newCall("questionableUnpack", expression)
+
   if name.kind == nnkIdent:
     quote do:
-      mixin questionableUnpack
-      let (`name` {.used.}, isOk) = questionableUnpack(`expression`)
+      let (`name` {.used.}, isOk) = `unpacker`
       isOk
 
   else:
     let name = name[0]
     quote do:
-      mixin questionableUnpack
-      var (`name` {.used.}, isOk) = questionableUnpack(`expression`)
+      var (`name` {.used.}, isOk) = `unpacker`
       isOk
diff --git a/questionable/results.nim b/questionable/results.nim
index 220dd1a..4f6cb7c 100644
--- a/questionable/results.nim
+++ b/questionable/results.nim
@@ -110,14 +110,21 @@ proc option*[T,E](value: Result[T,E]): ?T =
   else:
     T.none
 
-template questionableUnpack*[T, E](expression: Result[T, E]): (T, bool) =
+macro questionableUnpack*[T, E](expression: Result[T, E]): (T, bool) =
   ## Used internally
 
-  let res = expression
-  when declared(internalWithoutError):
-    if res.isFailure:
-      internalWithoutError = res.error
-  questionableUnpack(res.option)
+  # expression must be resolved before quote do to avoid binding issues
+  let
+    resSymbol = genSym()
+    res = newNimNode(nnkLetSection).add(
+      newIdentDefs(resSymbol, newEmptyNode(), expression)
+    )
+  quote do:
+    `res`
+    when declared(internalWithoutError):
+      if `resSymbol`.isFailure:
+        internalWithoutError = `resSymbol`.error
+    questionableUnpack(`resSymbol`.option)
 
 Result.liftUnary(`-`)
 Result.liftUnary(`+`)