Is Safe Haskell intended to allow segfaults?

Brandon Allbery allbery.b at
Mon Aug 8 17:34:36 UTC 2016

On Mon, Aug 8, 2016 at 1:27 PM, Ryan Newton <rrnewton at> wrote:

> As usual?  So it is ok to segfault GHC?  Elsewhere it says "in the safe
> language you can trust the types", and I'd always assumed that meant Safe
> Haskell is a type safe language, even in the IO fragment.

Pretty sure it's impossible to allow IO without enabling all of it one way
or another. And as soon as you allow *any* IO, you're open to various kinds
of failures including segfaults. The only way you will get your type system
to prevent that is fully specified dependent typing both in your program
*and in the OS level interfaces*. I wish you luck on the latter.

brandon s allbery kf8nh                               sine nomine associates
allbery.b at                                  ballbery at
unix, openafs, kerberos, infrastructure, xmonad
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