| ▲ | ux266478 3 days ago | |
While interesting on a surface level, I find this paper curious. What it describes here is essentially a roundabout way to try and express open type associations ("extending the data set" as it calls it) when the class hierarchy is already occupied as a primitive cognate to sum-types. This is more or less just a grammar to express type classes stapled over a class hierarchy grammar. I think the almost pun-like structure of that is funny, but in all actuality this feels pretty needless. The strangest aspect of it is that they cite Haskell. Given the date of the paper, I would understand unfamiliarity with Haskell given the implementations[1] that were available at the time weren't very "useful" if you had any kind of latency requirements on your software. That being said it's strange that somebody in 1998 would write a paper like this, know that Haskell was a thing, and also have no knowledge of type classes, which are explicitly designed to fill the role of open type sets. For those note in the know, functional languages tend to be able to express this open type association in various ways. Type classes are one way, another example beyond Haskell is MaPLe[2]. SML (and ML-only style OCAML) has a somewhat restricted form by way of its module and functor system, and eqtype. MLPolyR has an unrestricted form by way of row polymorphism. | ||