From e3178fb8d056b2e55f0baa041be313d9c4bd1ff4 Mon Sep 17 00:00:00 2001
From: Quinn Wilton <wilton@synopsys.com>
Date: Wed, 2 Dec 2020 11:33:39 -0800
Subject: Add bool.exclusive_nor

---
 src/gleam/bool.gleam       | 25 +++++++++++++++++++++++++
 test/gleam/bool_test.gleam | 14 ++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/src/gleam/bool.gleam b/src/gleam/bool.gleam
index e5b079f..0792057 100644
--- a/src/gleam/bool.gleam
+++ b/src/gleam/bool.gleam
@@ -55,6 +55,31 @@ pub fn exclusive_or(a: Bool, b: Bool) -> Bool {
   }
 }
 
+/// Returns the exclusive nor of two bools
+///
+/// ## Examples
+///
+///    > exclusive_nor(False, False)
+///    True
+///
+///    > exclusive_nor(False, True)
+///    False
+///
+///    > exclusive_nor(True, False)
+///    False
+///
+///    > exclusive_nor(True, True)
+///    True
+///
+pub fn exclusive_nor(a: Bool, b: Bool) -> Bool {
+  case a, b {
+    False, False -> True
+    False, True -> False
+    True, False -> False
+    True, True -> True
+  }
+}
+
 /// Compares two bools and returns the first values Order to the second.
 ///
 /// ## Examples
diff --git a/test/gleam/bool_test.gleam b/test/gleam/bool_test.gleam
index aced02b..c2ef78b 100644
--- a/test/gleam/bool_test.gleam
+++ b/test/gleam/bool_test.gleam
@@ -24,6 +24,20 @@ pub fn exclusive_or_test() {
   |> should.be_true
 }
 
+pub fn exclusive_nor_test() {
+  bool.exclusive_nor(False, False)
+  |> should.be_true
+
+  bool.exclusive_nor(False, True)
+  |> should.be_false
+
+  bool.exclusive_nor(True, False)
+  |> should.be_false
+
+  bool.exclusive_nor(True, True)
+  |> should.be_true
+}
+
 pub fn compare_test() {
   bool.compare(True, True)
   |> should.equal(order.Eq)
-- 
cgit v1.2.3