On Tue, Jun 05, 2007 at 10:49:00AM +0100, Simon Marlow wrote:
Ashley Yakeley wrote:
Can we move the other unsafe stuff into the Unsafe.* hierarchy?
It's not clear to me that Unsafe.System.IO would be better than System.IO.Unsafe. What is the primary purpose of unsafePerformIO - to do IO, or to be unsafe?
I see the point - to clearly separate all the unsafe stuff - but there are other categories of things that we might also want to separate (e.g. Haskell 98 vs. non-Haskell 98, portable vs. non-portable, deprecated vs. current...). We made the decision a long time ago that the hierarchy should categorise by functionality rather than any other property of modules. There are exceptions (System.Posix), but it's still a good rule of thumb.
indeed. I agree with this. also, I really dislike the 'unsafe' categorization as a catch all for all sorts of "bad" things. I mean, we don't have 'UnsafeIx' or, unsafePoke, but we have things like 'unsafeChr' when perhaps 'uncheckedChr' would have been more appropriate. Not that I am opposed to making it clear what side conditions the user needs to worry about when using a routine, but that is what liberal haddock documentation is for. I think unsafePerformIO and unsafeCoerce are good, because they both allow you to directly break the _static_ sematics of the language. as in, they directly subvert the type system. However, I think many of the other uses should be elided (with liberal documentation) or changed to something more appropriate. This is why I think an 'Unsafe.*' would be a bad idea. it would be a dumping ground for lots of routines with nothing in common other than it made someone uncomfortable at some point. I mean, think if all the ByteString functions dealing with pointers had to move there because you might pass in a bad pointer. We really need to stop using the terms 'safe' and 'unsafe' so much actually. like the recent suggestion of a '-fsafe' flag for ghc. does that mean it makes your code safer? from which use of safe? does it only allows safe code? or assumes your code is safe so turns off type checking? something like '-funtrusted' would be more descriptive and specific. John -- John Meacham - ⑆repetae.net⑆john⑈