Rename methods

Author: jakewhiteley

src/Set.php

@@ -142,7 +142,7 @@ public function values(): array
      * @param Set $set The set to append
      * @return Set A new set containing the merged items
      */
-    public function merge(Set $set): Set
+    public function unison(Set $set): Set
     {
         $merged = new Set();
         $merged->exchangeArray($this->values());
@@ -163,14 +163,14 @@ public function merge(Set $set): Set
      * @return Set
      *
      */
-    public function diff(Set $set): Set
+    public function difference(Set $set): Set
     {
         if ($this->size === 0) {
             return new Set();
         }
 
         if ($set->size === 0) {
-            return (new Set())->merge($this);
+            return (new Set())->unison($this);
         }
 
         $intersect = new Set;
@@ -184,6 +184,21 @@ public function diff(Set $set): Set
         return $intersect;
     }
 
+    public function symmetricDifference(Set $set): Set
+    {
+        $diff = clone $this;
+
+        foreach ($set->values() as $value) {
+            if ($diff->has($value)) {
+                $diff->delete($value);
+            } else {
+                $diff->add($value);
+            }
+        }
+
+        return $diff;
+    }
+
     /**
      * Checks if a given $set is a subset of the current instance
      * All values should be present, but ordinality does not matter

tests/SetTest.php

@@ -27,6 +27,16 @@ public function testAdd()
         $this->assertSame(['a'], $set->values());
     }
 
+    public function testAddViaArrayAccess()
+    {
+        $set = new Set();
+        $set[] = 'a';
+        $this->assertSame(['a'], $set->values());
+
+        $set[] ='a';
+        $this->assertSame(['a'], $set->values());
+    }
+
     public function testDelete()
     {
         $set = new Set();
@@ -70,7 +80,7 @@ public function testDiffOnSameValues()
         $set2->add(2);
 
         $expected = 0;
-        $result = $set->diff($set2)->size;
+        $result = $set->difference($set2)->size;
 
         $this->assertSame($expected, $result);
     }
@@ -80,7 +90,7 @@ public function testDiffOnDifferentValues()
         $set = new Set(1, 2);
         $set2 = new Set(3, 4);
 
-        $result = $set->diff($set2);
+        $result = $set->difference($set2);
 
         $this->assertSame(2, $result->size);
         $this->assertSame([1,2], $result->values());
@@ -91,7 +101,7 @@ public function testDiffOnEmptySet()
         $set = new Set();
         $set2 = new Set(3, 4);
 
-        $result = $set->diff($set2);
+        $result = $set->difference($set2);
         $this->assertSame(0, $result->size);
     }
 
@@ -100,7 +110,7 @@ public function testDiffOnEmptyTargetSet()
         $set = new Set(1,2);
         $set2 = new Set();
 
-        $result = $set->diff($set2);
+        $result = $set->difference($set2);
         $this->assertSame(2, $result->size);
     }
 
@@ -153,7 +163,7 @@ public function testMerge()
         $set2->add(null);
 
         $expected = [1, 2, null];
-        $result = $set->merge($set2)->values();
+        $result = $set->unison($set2)->values();
 
         $this->assertSame($expected, $result);
     }
@@ -213,4 +223,20 @@ public function testSubsetShouldReturnFalse()
 
         $this->assertFalse($set->subset($subset));
     }
+
+    public function testSymmetricDifference()
+    {
+        $set1 = new Set(1, 2, 'three');
+        $set2 = new Set(2, 3, 4);
+
+        $this->assertEquals([1, 'three', 3, 4], $set1->symmetricDifference($set2)->values());
+        $this->assertEqualsArray([1, 'three', 3, 4], $set2->symmetricDifference($set1)->values());
+    }
+
+    protected function assertEqualsArray($expected, $actual, $message = '')
+    {
+        sort($expected);
+        sort($actual);
+        $this->assertEquals($expected, $actual, $message);
+    }
 }