.

proto.js

@@ -96,6 +96,18 @@ load = function load() {
 			},
 			configurable: true
 		},
+		mapArr: {
+			value: function(fn) {
+				const mapped = new Array(this.length)
+
+				for (let i = 0; i < this.length; i++) {
+					mapped[i] = fn(this[i], i, this)
+				}
+
+				return mapped
+			},
+			configurable: true
+		},
 		sum: {
 			value: function(val = 0) {
 				return this.reduce((a, b) => a + b, val)
@@ -122,7 +134,7 @@ load = function load() {
 		},
 		transpose: {
 			value: function() {
-				return Array(this[0].length).fill().map((_, i) => this.map(e => e[i]))
+				return this[0].map((_, i) => this.map(e => e[i]))
 			},
 			configurable: true
 		},
@@ -154,7 +166,7 @@ load = function load() {
 			},
 			configurable: true
 		},
-		rotate: {
+		rotateLeft: {
 			value: function(n) {
 				let k = (this.length + n) % this.length
 				return [...this.slice(k), ...this.slice(0, k)]
@@ -294,19 +306,13 @@ load = function load() {
 			},
 			configurable: true
 		},
-		map: {
-			value: function(...args) {
-				return this.arr.map(...args)
-			},
-			configurable: true
-		},
 		splitOnElement: {
 			value: function(sep) {
-				let arr = [[]]
+				let arr = [new PointArray()]
 
 				for (let i = 0; i < this.length; i++) {
 					if (this[i].equals(sep)) {
-						arr.push([])
+						arr.push(new PointArray())
 					} else {
 						arr[arr.length - 1].push(this[i])
 					}
@@ -316,6 +322,41 @@ load = function load() {
 			},
 			configurable: true
 		},
+		map: {
+			value: function(fn) {
+				const mapped = new PointArray(this.length)
+
+				for (let i = 0; i < this.length; i++) {
+					mapped[i] = fn(this[i], i, this)
+				}
+
+				return mapped
+			},
+			configurable: true
+		},
+		cartProduct: {
+			value: function(that) {
+				return this.flatMap((e) => that.map((f) => new PointArray(e, f)))
+			},
+			configurable: true
+		},
+		interleave: {
+			value: function(that = new PointArray()) {
+				return new PointArray(this, that).transpose().flat()
+			},
+			configurable: true
+		},
+		rotateLeft: {
+			value: function(n) {
+				if (this.length == 1) {
+					return this.copy()
+				}
+
+				let k = (this.length + n) % this.length
+				return new PointArray(...this.slice(k), ...this.slice(0, k))
+			},
+			configurable: true
+		},
 		sort: {
 			value: function(func = (a, b) => a.readingOrderCompare(b)) {
 				return Array.prototype.sort.apply(this, func)