Merge pull request #126 from Lctrs/enumset-isempty

Add EnumSet::isEmpty() to know if sets has enumerators

Author: marc-mabe

README.md

@@ -262,6 +262,8 @@ $enumSet->has(UserStatus::INACTIVE); // bool
 $enumSet->count();
 count($enumSet);
 
+// Tests if it has enumerators
+$enumSet->isEmpty();
 
 // convert to array
 $enumSet->getValues();      // List of enumerator values

src/EnumSet.php

@@ -37,6 +37,13 @@ class EnumSet implements IteratorAggregate, Countable
      */
     private $bitset = 0;
 
+    /**
+     * Integer or binary (little endian) empty bitset
+     *
+     * @var int|string
+     */
+    private $emptyBitset = 0;
+
     /**#@+
      * Defines private method names to be called depended of how the bitset type was set too.
      * ... Integer or binary bitset.
@@ -79,7 +86,7 @@ public function __construct(string $enumeration, iterable $enumerators = null)
         // we will switch this into a binary bitset
         if ($this->enumerationCount > \PHP_INT_SIZE * 8) {
             // init binary bitset with zeros
-            $this->bitset = \str_repeat("\0", (int)\ceil($this->enumerationCount / 8));
+            $this->bitset = $this->emptyBitset = \str_repeat("\0", (int)\ceil($this->enumerationCount / 8));
 
             // switch internal binary bitset functions
             $this->fnDoGetIterator       = 'doGetIteratorBin';
@@ -1097,4 +1104,14 @@ private function doGetBitInt($ordinal)
     {
         return (bool)($this->bitset & (1 << $ordinal));
     }
+
+    /**
+     * Return true if the set is empty, false otherwise.
+     *
+     * @return bool
+     */
+    public function isEmpty(): bool
+    {
+        return $this->bitset === $this->emptyBitset;
+    }
 }

tests/MabeEnumTest/EnumSetTest.php

@@ -904,6 +904,22 @@ public function testSetSymDiffThrowsInvalidArgumentException()
         $set1->setSymDiff($set2);
     }
 
+    /**
+     * @dataProvider getIntegerEnumerations
+     */
+    public function testIsEmpty($enum)
+    {
+        $set1 = new EnumSet($enum, []);
+        $set2 = new EnumSet($enum, $enum::getValues());
+
+        $this->assertTrue($set1->isEmpty());
+        $this->assertFalse($set2->isEmpty());
+
+        $set2->removeIterable($enum::getValues());
+
+        $this->assertTrue($set2->isEmpty());
+    }
+
     /* deprecated */
 
     /** @deprecated */