On 11/20/06, Malcolm Wallace
Well, for one thing I don't like the idea of a "list" of potential defaults. My suggestion is that there should be a single default type per class. If more than one class is involved, then either their defaults should agree, or only one of them in fact declares a default.
I claim that this would be sufficient for every extant use case. But I would quite like to have some evidence to back up this claim! If anyone actually uses explicit defaults in their programs, I would be interested in seeing some real data on this. Feel free to submit such example decls to my email address. I suspect that almost no-one uses defaults except for the original motivating case of literal numbers. If so, then even quite a big change in this area would hurt very few people, provided it was backward compatible with the literal number thing.
Ah, another fine opportunity to use Google Code Search. And even more so now that it supports Haskell code! http://www.google.com/codesearch?hl=en&lr=&q=%5Edefault%5C+%3F%5C%28+lang%3Ahaskell&btnG=Search Cheers, Josef