Quoth Greg Weber <greg@gregweber.info>,
...
> Many of the built-in record proposals seem more ambitious (create a new
> record from an existing one, generalize in some other direction). More
> power or generalization could be very useful, but it can wait for later -
> Haskell's records are glaringly bad because they lack name-spacing.
>
> I think one of the problems being faced with improving records is a false
> choice between a quick but hacky library desugaring or a major "Extensible"
> records built into the compiler. What I am proposing is that (unless
> someone proposes a great desugaring solution) we make it the immediate goal
> to have records built into the compiler, but done in the simplest (perhaps
> least "Extensible") way that just accomplishes name-spacing.
It's sure easy to imagine something like that happening, in principle,
but ... are you saying that extensibility specifically has been a major
issue? Could be, I haven't been paying so much attention.
Yes, I believe it is common knowledge and stated in many places that the community cannot decide on the best *extensible* record system.
Wouldn't extensibility more or less come along with row polymorphism?
I mean, my understanding of the term is that an expression that
instantiates a particular record field, can incorporate a record lacking
that field, which seems to me to be implicit in row polymorphism anyway.
I would think row polymorphism is a must-have.
Perhaps if you want *extensible* records. If you would like to make some progress with records in the near future rather than keeping records in limbo, I think we really need to give up for the moment on any higher form of abstraction than straight-forward name-spacing.
If you're interested in looking at old, Haskell-related record systems,
also see O'Haskell.
I am interested in any potential solution. You could link to it on the ExtensibleRecords wiki page and explain it a bit for future reference. O'Haskell seems to be very much concerned with being as extensible as possible - to the point of trying to do OO in Haskell.
Greg Weber
Donn