This was already featured in the Weekly News a couple of weeks back, but I think maybe it deserves it’s own thread. I’ve tried to explain this approach to some people before, but I think this article does a much better job than I have....
But how? Parsing function can return any of the types, we don't know what was in the bytestring. So we'd need to deal with all variations in any case, no?
Is the difference in that it becomes possible to pattern-match on a type of an element inside the structure, rather than on the structure as a whole? So as long as you don't need that element, you can access elements that are common without pattern-matching? I guess it's a marginal benefit...
Defeating Return Type Polymorphism (philipphagenlocher.de)
This was already featured in the Weekly News a couple of weeks back, but I think maybe it deserves it’s own thread. I’ve tried to explain this approach to some people before, but I think this article does a much better job than I have....