added operator == and hashCode to BitSet

Author: denniskaselow

lib/src/bit_array.dart

@@ -1,7 +1,7 @@
 part of bit_array;
 
 /// Bit array to store bits.
-class BitArray implements BitSet {
+class BitArray extends BitSet {
   Uint32List _data;
   int _length;
 

lib/src/bit_set.dart

@@ -24,6 +24,32 @@ abstract class BitSet {
   /// Returns an iterable wrapper of the [BitSet] that iterates over the index
   /// members that are set to true.
   Iterable<int> asIntIterable();
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) {
+      return true;
+    }
+    if (other is BitSet &&
+        runtimeType == other.runtimeType &&
+        length == other.length) {
+      final iter = asUint32Iterable().iterator;
+      final otherIter = other.asUint32Iterable().iterator;
+      while (iter.moveNext() && otherIter.moveNext()) {
+        if (iter.current != otherIter.current) {
+          return false;
+        }
+      }
+      return true;
+    }
+    return false;
+  }
+
+  @override
+  int get hashCode =>
+      asUint32Iterable().fold(
+          0, (int previousValue, element) => previousValue ^ element.hashCode) ^
+      length.hashCode;
 }
 
 /// Memory-efficient empty [BitSet].
@@ -53,7 +79,7 @@ class EmptySet implements BitSet {
 const emptyBitSet = EmptySet();
 
 /// A list-based [BitSet] implementation.
-class ListSet implements BitSet {
+class ListSet extends BitSet {
   final List<int> _list;
 
   ListSet.fromSorted(this._list);
@@ -102,7 +128,7 @@ class ListSet implements BitSet {
 }
 
 /// A range-based [BitSet] implementation.
-class RangeSet implements BitSet {
+class RangeSet extends BitSet {
   final List<int> _list;
 
   RangeSet.fromSortedRangeLength(this._list);

lib/src/composite_set.dart

@@ -28,7 +28,7 @@ class BitSetChunk {
 ///
 /// By default, each chunk is using a maximum cardinality of 2^16 entries,
 /// following the RoaringBitmap pattern.
-class CompositeSet implements BitSet {
+class CompositeSet extends BitSet {
   /// The bits used for each chunk.
   final int chunkBits;
 

test/bit_array_test.dart

@@ -88,6 +88,24 @@ void main() {
     });
   });
 
+  group('BitArray equals and hashCode', () {
+    final oiii = BitArray(32)..setBits([1, 2, 3]);
+    final oioi = BitArray(32)..setBits([1, 3]);
+    final ooio = BitArray(32)..setBits([2]);
+
+    test('equals', () {
+      expect(oiii ^ oioi, equals(ooio));
+    });
+
+    test('not equals', () {
+      expect(oiii, isNot(ooio));
+    });
+
+    test('hashCode', () {
+      expect((oiii ^ oioi).hashCode, equals(ooio.hashCode));
+    });
+  });
+
   group('BitArray + BitSet', () {
     final array = BitArray(128)..setBits([13, 113]);
     final list = ListSet.fromSorted([13, 33]);

test/bit_set_test.dart

@@ -57,6 +57,21 @@ void main() {
     });
   });
 
+  group('ListSet equals and hashCode', () {
+    test('equals', () {
+      expect(ListSet.fromSorted([1, 3]), equals(ListSet.fromSorted([1, 3])));
+    });
+
+    test('not equals', () {
+      expect(ListSet.fromSorted([1, 3]), isNot(ListSet.fromSorted([1, 2])));
+    });
+
+    test('hashCode', () {
+      expect(ListSet.fromSorted([1, 3]).hashCode,
+          equals(ListSet.fromSorted([1, 3]).hashCode));
+    });
+  });
+
   group('RangeSet', () {
     final set = RangeSet.fromSortedRangeLength([2, 0, 6, 3, 15, 2, 21, 4]);
 
@@ -94,6 +109,23 @@ void main() {
       ]);
     });
   });
+
+  group('RangeSet equals and hashCode', () {
+    test('equals', () {
+      expect(RangeSet.fromSortedRangeLength([1, 3]),
+          equals(RangeSet.fromSortedRangeLength([1, 2, 4, 0])));
+    });
+
+    test('not equals', () {
+      expect(RangeSet.fromSortedRangeLength([1, 3]),
+          isNot(RangeSet.fromSortedRangeLength([1, 2])));
+    });
+
+    test('hashCode', () {
+      expect(RangeSet.fromSortedRangeLength([1, 3]).hashCode,
+          equals(RangeSet.fromSortedRangeLength([1, 2, 4, 0]).hashCode));
+    });
+  });
 }
 
 String _rev(String s) => String.fromCharCodes(s.codeUnits.reversed);

test/composite_set_test.dart

@@ -39,4 +39,33 @@ void main() {
       expect(set.asIntIterable().toList(), [65537]);
     });
   });
+
+  group('CompositeSet equals and hashCode', () {
+    final oiii = CompositeSet();
+    final oioi = CompositeSet();
+    final ooio = CompositeSet();
+
+    setUp(() {
+      oiii[1] = true;
+      oiii[2] = true;
+      oiii[3] = true;
+
+      oioi[1] = true;
+      oioi[3] = true;
+
+      ooio[2] = true;
+    });
+
+    test('equals', () {
+      expect(oioi..or(ooio), equals(oiii));
+    });
+
+    test('not equals', () {
+      expect(oiii, isNot(ooio));
+    });
+
+    test('hashCode', () {
+      expect((oioi..or(ooio)).hashCode, equals(oiii.hashCode));
+    });
+  });
 }