From dad28a269fa0838635a0310f9d1456680f7bbff5 Mon Sep 17 00:00:00 2001
From: Jacek Sieka <jacek@status.im>
Date: Fri, 17 Jun 2022 12:45:22 +0200
Subject: [PATCH] result: add `Opt.some` / `Opt.none` (#117)

---
 stew/results.nim       | 18 ++++++++++++++++++
 tests/test_results.nim |  4 +++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/stew/results.nim b/stew/results.nim
index 99bb5e2..b3e6a26 100644
--- a/stew/results.nim
+++ b/stew/results.nim
@@ -884,6 +884,24 @@ func filter*[T](
 
 # Options compatibility
 
+template some*[T](O: type Opt, v: T): Opt[T] =
+  ## Create an `Opt` set to a value
+  ##
+  ## ```
+  ## let o = Opt.some(42)
+  ## assert o.isSome and o.get() == 42
+  ## ```
+  Opt[T].ok(v)
+
+template none*(O: type Opt, T: type): Opt[T] =
+  ## Create an `Opt` set to none
+  ##
+  ## ```
+  ## let o = Opt.none(int)
+  ## assert o.isNone
+  ## ```
+  Opt[T].err()
+
 template isSome*(o: Opt): bool =
   ## Alias for `isOk`
   isOk o
diff --git a/tests/test_results.nim b/tests/test_results.nim
index 7d5734e..f6eb3e3 100644
--- a/tests/test_results.nim
+++ b/tests/test_results.nim
@@ -351,6 +351,9 @@ block: # Result[T, void] aka `Opt`
   doAssert oOk.filter(proc(x: int): bool = false).isErr()
   doAssert oErr.filter(proc(x: int): bool = true) == oErr
 
+  doAssert Opt.some(42).get() == 42
+  doAssert Opt.none(int).isNone()
+
 block: # `cstring` dangling reference protection
   type CSRes = Result[void, cstring]
 
@@ -398,4 +401,3 @@ block: # Experiments
     counter2 += 1
 
   doAssert counter2 == 1, "one-item collection when set"
-