wren ng thornton
FWIW, this is the concern I alluded to earlier. Namely that we may want to have two (or more), er, 'classes' of records--- where a field is polymorphic over an individual class, but we don't want those classes to merge simply because they happened to choose the same name and type for the field.
I agree 'classes' is a misleading word for that. Isn't what you want two (or more) namespaces for records -- that is, for their fields? This is the DORF approach. (Barney seems to be describing the SORF approach -- he's got DORF wrong.) One of the namespaces includes Product.name; another Person.name. (So I'm taking a namespace as equivalent to a module.) You can have multiple records with a `name` field in each module (Customer, Employee, Business Contact, etc) -- so this is already better than H98.) Providing you're coding in a module that imports only one of those namespaces, you can use `name` unqualified. If you're coding in a module that imports both, you must use `name` qualified. If you try to apply (Product.name customer) you'll get a type failure (no instance).
I'm not sure it's a good proposal, but it seems like the only way to handle this issue is to (1) introduce a new kind for semantically-oriented field names,
That's what SORF does: the String Kind
and (2) make the Has class use that kind rather than a type-level string.
No proposal is using a _type_-level string. Barney's confused you. DORF uses a type (regular importable/qualifiable/hidable) with a prefix to the field name: data Proxy_name Where you're in a module that imports both the `name`s per above, the desugarrer would generate Product.Proxy_name and Person.Proxy_name. (That's all rather awkward to get right, which is why I prefer the sugar.) By (1), what I mean is that rather
than referring to the field as "name", we would declare PersonalName and BrandName and then use those in lieu of the string. And if we do that, then (2) demands that we must somehow make explicit which one we mean, should we want the `name` field to be polymorphic for some given record declaration.
AntC