Dealing with imports and metadata

How do I pass external imports and metadata through the combinators? At the moment I use external lookup tables and collect this information through side effects. I also had to do `gen.printRuntime(d).replace(/\ninterface /, '\nexport interface ')` to export the brands since exporting them seemed to be necessary for things to work.

I'm trying to build a JSON Schema converter. An early development version of the converter is available at https://github.com/maasglobal/maas-schemas-ts/blob/master/converter.ts