Re: safe vs. unsafe (Was: Haskell Platform proposal: Add the vector package)

On 11 July 2012 23:45, Johan Tibell wrote:

On Wed, Jul 11, 2012 at 2:11 PM, Bas van Dijk wrote:

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On 11 July 2012 20:49, Henning Thielemann wrote:

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I think the idea was to have Unsafe modules and move the unsafe functions there. :-)

Indeed. I don't see the point about having .Safe modules. Modules should be safe by default as you mentioned before. I guess the reason we have .Safe modules in base and vector is for backwards compatibility.

The ideal, but currently, impossible way of dealing with this is to mark the _export_ of unsafe functions in a module as DEPRECATED and in a later version remove the unsafe functions and mark the module as Trustworthy. However this requires support for deprecating exports:

http://hackage.haskell.org/trac/ghc/ticket/4879

But why? The number of people who will benefit from this mass deprecation/mass migration is tiny.

While I agree that the number of people who will benefit is tiny I don't think it's a "mass" deprecation. In base there are only 7 functions that need to be deprecated: * Control.Monad.ST.Lazy.unsafeInterleaveST * Control.Monad.ST.Lazy.unsafeIOToST * Control.Monad.ST.unsafeInterleaveST * Control.Monad.ST.unsafeIOToST * Control.Monad.ST.unsafeSTToIO * Foreign.ForeignPtr.unsafeForeignPtrToPtr * Foreign.Marshal.unsafeLocalState And because of their unsafe nature are probably not used a lot, so the impact would not be big. However, I do think it's important to have the ability to first DEPRECATE the exports so users are warned well in advanced that they have to change their code. Bas