Separated parser class nodes and began writing compile methods

app/imports/parser/parseTree/SymbolNode.js

@@ -0,0 +1,24 @@
+import ParseNode from '/imports/parser/parseTree/ParseNode.js';
+import ConstantNode from '/imports/parser/parseTree/ConstantNode.js';
+
+export default class SymbolNode extends ParseNode {
+  constructor({name}){
+		super();
+    this.name = name;
+  }
+  compile(scope){
+    let value = scope && scope[this.name];
+    let type = typeof value;
+    if (type === 'string' || type === 'number' || type === 'boolean'){
+      return new ConstantNode({value, type});
+    } else if (type === 'undefined'){
+      return new ConstantNode({
+        value: this.name,
+        type: 'uncompiledNode',
+        errors: [`${this.name} could not be resolved`]
+      });
+    } else {
+      throw new Meteor.Error(`Unexpected case: ${this.name} resolved to ${value}`);
+    }
+  }
+}