Add bitwise AND, OR, and XOR operations

README.md

@@ -77,6 +77,18 @@ Gets the data with the integers holding the bits information. Ex: `new BitSet("1
 
 Returns the total number of bits set to 1 in this BitSet.
 
+**and(other)**
+
+Combines this BitSet with another BitSet of the same length using bitwise AND. The current BitSet is updated and returned.
+
+**or(other)**
+
+Combines this BitSet with another BitSet of the same length using bitwise OR. The current BitSet is updated and returned.
+
+**xor(other)**
+
+Combines this BitSet with another BitSet of the same length using bitwise XOR. The current BitSet is updated and returned.
+
 **invert()**
 
 Inverts this BitSet.

lib/BitSet.js

@@ -95,6 +95,27 @@ let BitSet = (function() {
 		return pos != null;
     }
 
+    //combines this BitSet with another using bitwise AND
+    BitSet.prototype.and = function(other) {
+        checkOtherParamTypeAndLength.call(this, other);
+        this[dataSymbol] = this[dataSymbol].map((x, i) => x & other[dataSymbol][i]);
+        return this;
+    }
+
+    //combines this BitSet with another using bitwise OR
+    BitSet.prototype.or = function(other) {
+        checkOtherParamTypeAndLength.call(this, other);
+        this[dataSymbol] = this[dataSymbol].map((x, i) => x | other[dataSymbol][i]);
+        return this;
+    }
+
+    //combines this BitSet with another using bitwise XOR
+    BitSet.prototype.xor = function(other) {
+        checkOtherParamTypeAndLength.call(this, other);
+        this[dataSymbol] = this[dataSymbol].map((x, i) => x ^ other[dataSymbol][i]);
+        return this;
+    }
+
     //inverts the array of bits
     BitSet.prototype.invert = function () {
         this[dataSymbol] = this[dataSymbol].map(x => ~x);

lib/BitSetES5.js

@@ -104,6 +104,33 @@ var BitSet = (function () {
         return pos != null;
     };
 
+    //combines this BitSet with another using bitwise AND
+    BitSet.prototype.and = function (other) {
+        checkOtherParamTypeAndLength.call(this, other);
+        this[dataSymbol] = this[dataSymbol].map(function (x, i) {
+            return x & other[dataSymbol][i];
+        });
+        return this;
+    };
+
+    //combines this BitSet with another using bitwise OR
+    BitSet.prototype.or = function (other) {
+        checkOtherParamTypeAndLength.call(this, other);
+        this[dataSymbol] = this[dataSymbol].map(function (x, i) {
+            return x | other[dataSymbol][i];
+        });
+        return this;
+    };
+
+    //combines this BitSet with another using bitwise XOR
+    BitSet.prototype.xor = function (other) {
+        checkOtherParamTypeAndLength.call(this, other);
+        this[dataSymbol] = this[dataSymbol].map(function (x, i) {
+            return x ^ other[dataSymbol][i];
+        });
+        return this;
+    };
+
     //inverts the array of bits
     BitSet.prototype.invert = function () {
         this[dataSymbol] = this[dataSymbol].map(function (x) {

spec/bitset.test.js

@@ -130,3 +130,35 @@ describe('Initialize a bitSet with a string', () => {
 
 
 });
+
+describe('Bitwise operations', () => {
+
+    it('combines BitSets with AND', () => {
+        let bitset = new BitSet("1100");
+        let other = new BitSet("1010");
+
+        expect(bitset.and(other).stringify()).toBe("1000");
+    });
+
+    it('combines BitSets with OR', () => {
+        let bitset = new BitSet("1100");
+        let other = new BitSet("1010");
+
+        expect(bitset.or(other).stringify()).toBe("1110");
+    });
+
+    it('combines BitSets with XOR', () => {
+        let bitset = new BitSet("1100");
+        let other = new BitSet("1010");
+
+        expect(bitset.xor(other).stringify()).toBe("0110");
+    });
+
+    it('rejects BitSets with different lengths', () => {
+        let bitset = new BitSet("1100");
+        let other = new BitSet("10");
+
+        expect(() => bitset.and(other)).toThrow("Only can modify BitSets with the same length");
+    });
+
+});