From 2f656a81c81a35d7d63bc67e9e0828b25fcca895 Mon Sep 17 00:00:00 2001
From: Peter Saxton <peterhsaxton@gmail.com>
Date: Wed, 2 Dec 2020 16:46:43 +0000
Subject: add lazy unwrap

---
 src/gleam/result.gleam | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 'src')

diff --git a/src/gleam/result.gleam b/src/gleam/result.gleam
index 76ee0e1..c381cae 100644
--- a/src/gleam/result.gleam
+++ b/src/gleam/result.gleam
@@ -165,6 +165,24 @@ pub fn unwrap(result: Result(a, e), or default: a) -> a {
   }
 }
 
+/// Extract the Ok value from a result, evaluating the default function if the result
+/// is an Error.
+///
+/// ## Examples
+///
+///    > unwrap(Ok(1), fn() { 0 })
+///    1
+///
+///    > unwrap(Error(""), fn() { 0 })
+///    0
+///
+pub fn lazy_unwrap(result: Result(a, e), or default: fn() -> a) -> a {
+  case result {
+    Ok(v) -> v
+    Error(_) -> default()
+  }
+}
+
 /// Transforms any error into Error(Nil)
 ///
 /// ## Examples
-- 
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