Does such thing as a deprecation pragma for an instance exist? What triggers it?
Roman * Johan Tibell <johan.tib...@gmail.com> [2013-06-11 14:18:41-0700] > If we truly believe that the instance is dangerous for users (and not > merely for people who don't understand floating point arithmetic on > computers), then we should add a deprecation pragma to the instance and > discourage its use. But what would the deprecation message encourage > instead, for users to write an explicit loop that tests against some > lower/upper bound? It would have the same problem as enumFromTo. I think > the issue here is really that floating point math on computers is hard to > think about. > > > On Tue, Jun 11, 2013 at 11:18 AM, harry <volderm...@hotmail.com> wrote: > > > Johan Tibell <johan.tibell@...> writes: > > > > > I don't see much gain. It will break previously working code and the > > workaround to the breakage will likely be manually reimplementing > > enumFromTo > > in each instance. > > > > I forgot the main point of my post :-) > > > > The primary motivation for removing these instances is that they cause > > endless confusion for beginners, e.g. > > > > http://stackoverflow.com/questions/13203471/the-math-behind-1-0999999999999999-in-haskell > > , > > http://stackoverflow.com/questions/9810002/floating-point-list-generator, > > http://stackoverflow.com/questions/7290438/haskell-ranges-and-floats, > > > > http://stackoverflow.com/questions/10328435/how-to-solve-floating-point-number-getting-wrong-in-list-haskell > > , > > and many more. > > > > On the other hand, how much working code is there "correctly" using there > > instances? > > > > > > _______________________________________________ > > Haskell-prime mailing list > > Haskell-prime@haskell.org > > http://www.haskell.org/mailman/listinfo/haskell-prime > > > _______________________________________________ > Haskell-prime mailing list > Haskell-prime@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-prime _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime