Added not operator to the parser

app/imports/parser/parseTree/NotOperatorNode.js

@@ -0,0 +1,27 @@
+import ParseNode from '/imports/parser/parseTree/ParseNode.js';
+import ConstantNode from '/imports/parser/parseTree/ConstantNode.js';
+
+export default class NotOperatorNode extends ParseNode {
+  constructor({right}) {
+		super(...arguments);
+    this.right = right;
+  }
+  resolve(fn, scope, context){
+    let rightNode = this.right[fn](scope, context);
+    if (!(rightNode instanceof ConstantNode)){
+      return new NotOperatorNode({
+        right: rightNode,
+      });
+    }
+    let right = rightNode.value;
+    let result = !right;
+    return new ConstantNode({
+      value: result,
+      type: typeof result,
+    });
+  }
+  toString(){
+    let {right} = this;
+    return `!${right.toString()}`;
+  }
+}

app/imports/parser/parseTree/OperatorNode.js

@@ -13,7 +13,7 @@ export default class OperatorNode extends ParseNode {
     let leftNode = this.left[fn](scope, context);
     let rightNode = this.right[fn](scope, context);
     let left, right;
-    if (leftNode.type !== 'number' || rightNode.type !== 'number'){
+    if (!(leftNode instanceof ConstantNode) || !(rightNode instanceof ConstantNode)){
       return new OperatorNode({
         left: leftNode,
         right: rightNode,