I have only tested it for a few hours using the tutorial, nevertheless I would like to make a few comments:
* It is quite quite slow. Have you consider any other language? I think it is written in Java; another language may be faster.
* The editor it is not very friendly, besides most programmer use to type very fast, I think it would be convinient to be able to write directly in plain text.

Did you regenerate your generator?
What code did you put in reference macro?
Did you put OutputFieldDeclaration label on declaration of output fields?

“Now let’s do the same thing with output fields. Again, we need to create the initialization code, and surround it with a $LOOP$ macro. Create a label for field declaration and put it on outputField’s $LOOP$. Then we need to use this label to create a reference. Your code in the template should look like this after making these changes : ”

But if I add a reference macro to outputField, the generated code is this.null. If I leave it without any reference macro, the generated code is correct: this.outputField0.

Did I do something wrong or something?

You need to create a mapping label with a name InputFieldDeclaration. With type InputField -> FieldDeclaration. Take a look at the following screenshot:

I’m kind of stuck in the middle of the Calculator tutorial because there seems to be an error in the “Implementing generator” section. The image after “Go to mapping and add this:” is the same as the previous one (image082) so it doesn’t give much information about what to do.