From 86711b9bf0dff8ff13a981adcd733ea8ac3526ca Mon Sep 17 00:00:00 2001
From: Maxi Benedetto <maxi@falconer.com>
Date: Tue, 1 Sep 2026 08:04:00 +0000
Subject: [PATCH] Add bitwise AND OR and XOR operations

---
 README.md           | 12 ++++++++++++
 lib/BitSet.js       | 21 +++++++++++++++++++++
 lib/BitSetES5.js    | 27 +++++++++++++++++++++++++++
 spec/bitset.test.js | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 92 insertions(+)

diff --git a/README.md b/README.md
index 93b8aca..1e6c29d 100644
--- a/README.md
+++ b/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.
diff --git a/lib/BitSet.js b/lib/BitSet.js
index 9fbb704..91cef8b 100644
--- a/lib/BitSet.js
+++ b/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);
diff --git a/lib/BitSetES5.js b/lib/BitSetES5.js
index 8e22b0e..d9ef729 100644
--- a/lib/BitSetES5.js
+++ b/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) {
diff --git a/spec/bitset.test.js b/spec/bitset.test.js
index 1782ead..df303f4 100644
--- a/spec/bitset.test.js
+++ b/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");
+    });
+
+});