From 89850aab50d62676cde5447b3fec220f11852ac7 Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Thu, 15 Apr 2021 10:54:50 +0200
Subject: [PATCH] =?UTF-8?q?Makes=20|=3F,=20=3D=3F=20and=20.option=20compat?=
 =?UTF-8?q?ible=20with=20other=20types=20of=20Result?=

---
 questionable/results.nim    | 31 ++++++++++++++++++-------------
 testmodules/result/test.nim | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/questionable/results.nim b/questionable/results.nim
index fc7dfa0..bfeaaeb 100644
--- a/questionable/results.nim
+++ b/questionable/results.nim
@@ -47,25 +47,30 @@ template `->?`*[T,U,V](values: (?!T, ?!U), expression: V): ?!V =
   else:
     expression.success
 
-template `|?`*[T](value: ?!T, fallback: T): T =
+template `|?`*[T,E](value: Result[T,E], fallback: T): T =
   value.valueOr(fallback)
 
-template `=?`*[T](name: untyped{nkIdent}, expression: ?!T): bool =
-  let value = expression
-  template name: T {.used.} = value.unsafeGet()
-  value.isSuccess
-
-macro `=?`*[T](variable: untyped{nkVarTy}, expression: ?!T): bool =
-  let name = variable[0]
+macro `=?`*[T,E](name: untyped{nkIdent}, expression: Result[T,E]): bool =
+  let unsafeGet = bindSym"unsafeGet"
+  let isOk = bindSym"isOk"
   quote do:
     let value = `expression`
-    var `name` : typeof(value.unsafeGet())
-    if value.isSuccess:
-      `name` = value.unsafeGet()
-    value.isSuccess
+    template `name`: T {.used.} = value.`unsafeGet`()
+    `isOk`(value)
+
+macro `=?`*[T,E](variable: untyped{nkVarTy}, expression: Result[T,E]): bool =
+  let name = variable[0]
+  let unsafeGet = bindSym"unsafeGet"
+  let isOk = bindSym"isOk"
+  quote do:
+    let value = `expression`
+    var `name` : typeof(value.`unsafeGet`())
+    if `isOk`(value):
+      `name` = value.`unsafeGet`()
+    `isOk`(value)
 
 proc option*[T,E](value: Result[T,E]): ?T =
-  if value.isSuccess:
+  if value.isOk:
     value.unsafeGet.some
   else:
     T.none
diff --git a/testmodules/result/test.nim b/testmodules/result/test.nim
index 5fdf56a..f6ba756 100644
--- a/testmodules/result/test.nim
+++ b/testmodules/result/test.nim
@@ -193,3 +193,21 @@ suite "result":
 
     let converted = works().option
     check (converted == @[1, 1, 2, 2, 2].some)
+
+import pkg/questionable/resultsbase
+
+suite "result compatibility":
+
+  test "|?, =? and .option work on other types of Result":
+    type R = Result[int, string]
+    let good = R.ok 42
+    let bad = R.err "error"
+
+    check bad |? 43 == 43
+
+    if value =? good:
+      check value == 42
+    else:
+      fail
+
+    check good.option == 42.some