29 Apr
2005
29 Apr
'05
8:56 a.m.
Philippa Cowderoy
On Fri, 29 Apr 2005, Simon Peyton-Jones wrote:
2. Use sub-typing, so that a value (Left x) is *both* in type Either and in type NEither. This opens a very large and complicated design space, as Ben mentioned.
I've been playing with this design space for a while and think there's at least one reasonable solution in it
What about "polymorphic variants" [1] ? They are definitely in the solution space, and work very well in Ocaml. Jacques [1] multiple papers, all downloadable from http://wwwfun.kurims.kyoto-u.ac.jp/~garrigue/papers/