From 1ad83adc9df257e4b5507c73f0d17abfdd534419 Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Mon, 8 Mar 2021 17:48:07 +0100
Subject: [PATCH] Convert Result to Option

---
 Readme.md                   | 8 ++++++++
 questionable/results.nim    | 7 +++++++
 testmodules/result/test.nim | 5 +++++
 3 files changed, 20 insertions(+)

diff --git a/Readme.md b/Readme.md
index 11d8a88..93e0848 100644
--- a/Readme.md
+++ b/Readme.md
@@ -179,6 +179,14 @@ let x = parseInt("42").catch  # equals 42.success
 let y = parseInt("XX").catch  # equals int.failure(..)
 ```
 
+### Conversion to Option
+
+Any Result can be converted to an Option:
+
+```nim
+let converted = works().toOption  # equals @[1, 1, 2, 2, 2].some
+```
+
 Banning Errors
 --------------
 
diff --git a/questionable/results.nim b/questionable/results.nim
index fee6acc..98eaf86 100644
--- a/questionable/results.nim
+++ b/questionable/results.nim
@@ -1,3 +1,4 @@
+import ./options
 import ./resultsbase
 
 include ./errorban
@@ -27,6 +28,12 @@ template `=?`*[T](name: untyped{nkIdent}, value: ?!T): bool =
   template name: T {.used.} = value.unsafeGet()
   value.isOk
 
+proc toOption*[T,E](value: Result[T,E]): ?T =
+  if value.isOk:
+    value.unsafeGet.some
+  else:
+    T.none
+
 template liftUnary(_: type Result, operator: untyped) =
 
   template `operator`*(a: ?!typed): ?!typed =
diff --git a/testmodules/result/test.nim b/testmodules/result/test.nim
index e91f1a5..630a7c5 100644
--- a/testmodules/result/test.nim
+++ b/testmodules/result/test.nim
@@ -1,6 +1,7 @@
 import std/unittest
 import std/sequtils
 import std/strutils
+import pkg/questionable
 import pkg/questionable/results
 
 suite "result":
@@ -94,6 +95,10 @@ suite "result":
     check (40.success >= 42 == false.success)
     check (40.success > 42 == false.success)
 
+  test "Result can be converted to Option":
+    check 42.success.toOption == 42.some
+    check int.failure(error).toOption == int.none
+
   test "examples from readme work":
 
     proc works: ?!seq[int] =