The proposal has this sentence, apparently in reference to using qualified imports: "This is sufficient, but it is just sufficiently inconvenient that people don't use it much." Does this mean qualified imports? I use them exclusively, and I'd love it if everyone else used them too.
Anyway, a few concerns about TDNR as prosposed: One thing I'd really like that this would provide is shorter record selection. "b.color" is a lot nicer than "Button.btn_color b". Or would it? It seems like under a TDNR scheme to be able to write "b.color" I'd have to either import "color" explicitly or go over to the unqualified import world. I don't really want to do the latter, but I also wouldn't want to maintain explicit import lists. Also, as far as I can see this doesn't provide is nice record update syntax. If I can write "b.color" I want to be able to write "b2 = b.color := red"! I think this will also lead to either lots of name shadowing warnings or more trouble picking variable names. The short perspicuous names this allows are also the most convenient for local variables. I don't want to suddenly not be able to use a 'color' variable name because some record has a 'color' field. A record system (and OO languages) would have no trouble with 'let color = b.color' but as far as I can see TDNR would have a problem. So as far as records, TDNR doesn't seem too satisfactory. I'm also worried about the use of dot with regards to a possible future record system. If we're already using dot for TDNR it's seems like it would be even harder for a record system to use it. I'm not saying this very well, but it seems like both proposals solve overlapping problems: TDNR provides convenient "method" calls and convenient field access as a side-effect, a record system would provide convenient field access and some form of subtyping. I think records are more interesting and I worry that TDNR would lessen motivation to implement records or make them more tricky to implement. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
