On Wed, Jul 11, 2012 at 7:27 PM, Johan Tibell
For example, most functions in bytestring are unsafe because their implementation uses unsafePerformIO. To be very concrete, if 'map' on ByteStrings is unsafe it needs to be moved from
While I share your distrust of the whole Safe Haskell movement as being a lot of effort for an unproven benefit from a definition of "safe" that is not demonstrated to be of practical usefulness or practical concern, I think you're wrong here. unsafePerformIO is unsafe. Data.ByteString.map is only unsafe if it allows unsafePerformIO to be abused. If it can verify that nothing actually unsafe takes place — which it does, by dint of the promise inherent in it being exposed as pure — Data.ByteString.map is *not* unsafe. The mechanical application of "oh, it uses unsafePerformIO, we don't care whether it proves it has used it safely: it must by definition be unsafe" just complicates things even more. If indeed it's not simply a strawman. -- brandon s allbery allbery.b@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms