Add xor operation to the base standard library

Should xor have a corresponding infix operator?

Author: mariari

Diff for: Stdlib/Data/Bool/Base.juvix

@@ -37,5 +37,11 @@ or (a b : Bool) : Bool := a || b;
 --- Logical conjunction.
 and (a b : Bool) : Bool := a && b;
 
+--- Logical exclusive or.
+xor : Bool -> Bool -> Bool
+  | true true := false
+  | false flase := false
+  | _ _ := true;
+
 builtin assert
 assert (x : Bool) : Bool := x;

Diff for: test/Test/Prelude.juvix

@@ -4,7 +4,15 @@ import Test.JuvixUnit open;
 import Stdlib.Prelude open;
 
 tests : List Test :=
-  [testCase "And" (assertEqual "and works as expected" (and true false) false)];
+  [
+    testCase "And" (assertEqual "and works as expected" (and true false) false);
+    testCase
+      "Xor"
+      (assertEqual "and works as expected" (xor true false) (xor false true));
+    testCase
+      "Xor-2"
+      (assertEqual "and works as expected" (xor false false) (xor true true));
+  ];
 
 suite : TestSuite := testSuite "Prelude" tests;