diff --git a/helpers.js b/helpers.js
new file mode 100644
index 0000000..d48a9fb
--- /dev/null
+++ b/helpers.js
@@ -0,0 +1,183 @@
+// general utilities
+class Command {
+ constructor(subject){
+ this._subject = subject;
+ this.commandsExecuted = [];
+ }
+
+ execute(command) {
+ this.commandsExecuted.push(command);
+ return this._subject[command]();
+ }
+
+}
+
+// Receiver:
+// knows how to carry out the operations associated with the command
+class UI {
+ constructor(userInput) {
+ this._userInput = userInput;
+ this._emoji = "🍍";
+ }
+
+ set userInput (userInput) {
+ this._userInput = userInput;
+ }
+
+ set emoji(newEmoji) {
+ this._emoji = newEmoji || "🍍";
+ }
+
+ // draw pineapples
+ // input: number of pineapples to draw
+ // out : html element
+ draw() {
+ const numElemToDraw = this._userInput;
+ return this._draw(numElemToDraw, 'p');
+ }
+
+
+ drawMultiple() {
+ // in: column row
+ // out htmlDocFragElement
+ const instructions = this._userInput.split(' ');
+ const columns = instructions[0];
+ const rows = instructions[1];
+ const docFragment = document.createDocumentFragment();
+ for (let i = 0; i < rows; i++ ) {
+ docFragment.appendChild(this._draw(columns,'p'))
+ }
+ return docFragment;
+ }
+
+ drawTriangle() {
+ const baseNumber = this._userInput.split(' ')[1];
+ const docFrag = document.createDocumentFragment();
+ for (let i = 1; i <= baseNumber; i++) {
+ docFrag.appendChild(this._draw(i, 'p'));
+ }
+ return docFrag;
+ }
+
+ drawRTriangle() {
+ const baseNumber = this._userInput.split(' ')[1];
+ const docFrag = document.createDocumentFragment();
+ for (let i = 1; i <= baseNumber; i++ ) {
+ const spacesToInsertBefore = baseNumber - i;
+ let trianglePartialElem = this._draw(i, 'p');
+ let temp = trianglePartialElem.textContent;
+ temp = this._insertSpace(spacesToInsertBefore) + temp;
+ trianglePartialElem.innerHTML = temp;
+ docFrag.appendChild(trianglePartialElem);
+ }
+ return docFrag;
+ }
+
+ drawETriangle() {
+ console.log("draw e triangle");
+ const baseNumber = parseInt(this._userInput.split(' ')[1]);
+ const docFrag = document.createDocumentFragment();
+ for (let i = baseNumber; i > 0; i-- ) {
+ const spacesToInsertBefore = i + (i-1);
+ let trianglePartialElem = this._draw( baseNumber - i + 1, 'p');
+ let temp = trianglePartialElem.textContent;
+ temp = this._insertSpace(spacesToInsertBefore) + temp;
+ trianglePartialElem.innerHTML = temp;
+ docFrag.appendChild(trianglePartialElem);
+ }
+ return docFrag;
+ }
+
+ drawEuTriangle() {
+ console.log("draw eu triangle");
+ const baseNumber = parseInt(this._userInput.split(' ')[1]);
+ const docFrag = document.createDocumentFragment();
+ for (let i = 0; i < baseNumber; i++ ) {
+ const spacesToInsertBefore = i + (i);
+ let trianglePartialElem = this._draw( baseNumber - i , 'p');
+ let temp = trianglePartialElem.textContent;
+ temp = this._insertSpace(spacesToInsertBefore) + temp;
+ trianglePartialElem.innerHTML = temp;
+ docFrag.appendChild(trianglePartialElem);
+ }
+ return docFrag;
+ }
+
+ _draw (colsToDraw, elementToReturn, symbol = this._emoji){
+ let newElem = document.createElement(elementToReturn);
+ for (let i = 0; i < colsToDraw; i++) {
+ newElem .textContent += symbol;
+ }
+ return newElem;
+ }
+
+ _insertSpace(numSpace) {
+ return " ".repeat(numSpace);
+ }
+
+ drawSquare() {
+ const size = this._userInput.split(' ')[2];
+ const docFrag = document.createDocumentFragment();
+ for (let i = 1 ; i <= size; i++ ) {
+ docFrag.appendChild(this._draw(size, 'p', "⬜"))
+ }
+ return docFrag;
+ }
+
+ // takes in direction, distance, current x, current y, size
+ // returns new square
+ moveCursor() {
+ }
+
+}
+
+class Helpers {
+ static isInputANumber (input) {
+ return !isNaN(parseInt(input));
+ }
+
+ static isDrawSingleRowCommand(input) {
+ return Helpers.isInputANumber(input) && input.split(' ').length === 1;
+ }
+
+ static isDrawMultipleColumnCommand(input) {
+ return Helpers.isInputANumber(input) && input.split(' ').length === 2;
+ }
+
+ static isClearCommand(input) {
+ return input === "clear" ;
+ }
+
+ static isDrawTriangleCommand(input) {
+ let re = new RegExp('^\\btriangle\\b \\d+$');
+ return re.test(input);
+ }
+
+ static isDrawSquareCommand(input) {
+ return input.includes("draw square");
+ }
+
+ static isDrawReverseTriangleCommand(input) {
+ let re = new RegExp('^\\brtriangle\\b \\d+$');
+ return re.test(input);
+ }
+
+ static isMoveCommand(input) {
+ let re = new RegExp('^\\bmove(up|down|left|right)\\b \\d+$');
+ return re.test(input);
+ }
+
+ static isEtriangleCommand(input) {
+ let re = new RegExp('^\\betriangle\\b \\d+$');
+ return re.test(input);
+ }
+
+ static isEuTriangleCommand(input) {
+ let re = new RegExp('^\\beutriangle\\b \\d+$');
+ return re.test(input);
+ }
+}
+String.prototype.replaceAt=function(index, replacement) {
+ return this.substr(0, index) + replacement+ this.substr(index + replacement.length);
+};
+
diff --git a/index.html b/index.html
index 77832ae..42f9008 100644
--- a/index.html
+++ b/index.html
@@ -14,6 +14,7 @@ output:
});
+