the_girabbit

Yeah, but it’s a schema-less, self-describing data format. It’s not like a specific position in a data stream has a requirement to be a specific type.

I can see why sum types would be useful in a schema or for the elements of a collection that is required to be homogeneous (ie. List<Foo|Bar>).

For what use case would one use custom sum types in a schema-less data format?

Ion will be even better for (structured) logging if this proposal for templates ever happens. https://github.com/amzn/ion-docs/pull/104

Looks like no one’s even so much as commented on it in the last year, so it might have been abandoned.

Comments don’t persist in binary. Like white space, they are explicitly not part of the data model.

Genuine question—why would you need a sum type in a self-describing data format?