Began work on rewriting parser without object orientation

Parsing is expensive, if the parse tree can be stored on the DB it can 
save a lot of compute time, but mongo can't store Classes, so we 
re-write without classes

app/imports/parser/parseTree/accessor.js

@@ -0,0 +1,66 @@
+import constant from './constant.js';
+
+const accessor = {
+  create({name, path}) {
+    return {
+      type: 'accessor',
+      path,
+      name,
+    };
+  },
+  compile(node, scope, context){
+    let value = scope && scope[node.name];
+    // For objects, get their value
+    node.path.forEach(name => {
+      if (value === undefined) return;
+      value = value[name];
+    });
+    let valueType = typeof value;
+    if (valueType === 'string' || valueType === 'number' || valueType === 'boolean'){
+      return {
+        result: constant.create({
+          value,
+          valueType
+        }),
+        context,
+      };
+    } else if (valueType === 'undefined'){
+      return {
+        result: accessor.create({
+          name: node.name,
+          path: node.path,
+        }),
+        context,
+      };
+    } else {
+      context.error(`${node.name} returned an unexpected type`);
+      return {
+        result: accessor.create({
+          name: node.name,
+          path: node.path,
+        }),
+        context,
+      };
+    }
+  },
+  reduce(node, scope, context){
+    let { result } = accessor.compile(node, scope, context);
+    if (result.type === 'accessor'){
+      context.error(`${accessor.toString(result)} not found, set to 0`);
+      return {
+        result: constant.create({
+          value: 0,
+          valueType: 'number',
+        }),
+        context
+      };
+    } else {
+      return {result, context};
+    }
+  },
+  toString(node){
+    return `${node.name}.${node.path.join('.')}`;
+  }
+}
+
+export default accessor;