[TYPES] Typing extensible records without row variables?

[Matthias Blume]

On Aug 25, 2008, at 8:55 PM, Brian Hulley wrote:

> 3) While it is obviously useful to have extensible records it is not  
> at
> all clear to me whether or not extensible variants are similarly  
> useful
> since there are other ways of achieving extensiblility in functional
> programming e.g. by adding new combinators to a combinator library and
> keeping the underlying representation variant completely hidden.

In our ICFP'06 paper[*] we suggest that extensible variants (actually:  
extensible cases)
might be a useful programming concept that integrates gracefully into  
an ML-
(or Haskell-) like language after all.

ou might also be interested in having a look at our upcoming APLAS  
paper[**],
where we point out that the same idea not only straightforwardly  
extends to the
typing of exceptions (a fact that has been exploited several times in  
previous work
on exception analysis by other authors), but also can be taken as a  
starting point
for a language design that (a) rules out any uncaught exceptions, and  
(b) integrates
well with the notion of extensible records and cases.

Matthias

[*] Extensible Programming with First-Class Cases.
     Matthias Blume, Umut A. Acar and Wonseok Chae.
     In Proceedings of the 11th ACM SIGPLAN International Conference  
on Functional Programming (ICFP'06).
     Portland, Oregon. Sep 18-20, 2006.

[**] Exception Handlers as Extensible Cases.
      Matthias Blume, Umut A. Acar, and Wonseok Chae.
      To appear in Proceedings of the Sixth ASIAN Symposium on  
Programming Languages and Systems (APLAS 2008).
      Bangalore, India, Dec 9-11, 2008.
      An expanded version is available as University of Chicago CS  
Technical Report TR-2008-03.