Implement disjoint method for traversable (#86)

Author: akondas

src/Collection/Traversable.php

@@ -117,6 +117,27 @@ public function filterNot(callable $predicate)
         });
     }
 
+    /**
+     * Returns true if the two specified collections have no elements in common.
+     *
+     * @param Traversable<T> $traversable
+     */
+    public function disjoint(self $traversable): bool
+    {
+        if ($this->isEmpty() || $traversable->isEmpty()) {
+            return true;
+        }
+
+        $iterator = $traversable->getIterator();
+        while ($iterator->hasNext()) {
+            if ($this->contains($iterator->next())) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     /**
      * @return T
      */

tests/Collection/SetTest.php

@@ -264,4 +264,15 @@ public function testSetRemoveAll(): void
         self::assertTrue(Set::ofAll(['alpha', 'beta', 'gamma'])->removeAll(Set::ofAll(['1', '2', '3']))->equals(Set::ofAll(['alpha', 'beta', 'gamma'])));
         self::assertTrue(Set::ofAll(['alpha', 'beta', 'gamma'])->removeAll(Set::ofAll(['1', '2', 'gamma']))->equals(Set::ofAll(['alpha', 'beta'])));
     }
+
+    public function testSetDisjoint()
+    {
+        self::assertTrue(Set::of('a', 'b', 'c')->disjoint(Set::empty()));
+        self::assertTrue(Set::empty()->disjoint(Set::of('a', 'b', 'c')));
+        self::assertTrue(Set::of('a', 'b', 'c')->disjoint(Set::of('d', 'e', 'f')));
+
+        self::assertFalse(Set::of('a', 'b', 'c')->disjoint(Set::of('a', 'e', 'f')));
+        self::assertFalse(Set::of('a', 'b', 'c')->disjoint(Set::of('d', 'b', 'f')));
+        self::assertFalse(Set::of('a', 'b', 'c')->disjoint(Set::of('d', 'e', 'c')));
+    }
 }