Re: Haskell Platform proposal: Add the vector package

On 18/06/2012, at 19:39, Johan Tibell wrote:

On Mon, Jun 18, 2012 at 9:54 AM, Bas van Dijk wrote:

...

I like the idea of the vector-safe package. Are you also proposing to add this package to the HP? (I would also be +1 on that)

I think it makes sense as a separate package, but I don't think it makes sense to add to the HP. SafeHaskell isn't used enough to warrant that.

I fully agree with Johan and I wouldn't even really want to maintain this separate package. It is a lot of work for something I don't use and don't entirely understand. The *.Safe modules in vector are currently bitrotted since I forget to update them when I add new operations and I'm not really sure what is and isn't "safe" anyway. Is anybody interested in this code at all?

...

I see that the trustworthiness of the .Safe modules is conditional on whether bound checking is enabled in vector:

#if defined(VECTOR_BOUNDS_CHECKS) {-# LANGUAGE Trustworthy #-} #endif

The VECTOR_BOUNDS_CHECKS pragma would not be directly available in vector-safe. But I guess, by using the install-includes cabal field, vector can export a header file that exports this symbol when bound checking is enabled.

That sounds like a reasonable solution.

VECTOR_BOUNDS_CHECKS is defined in vector.cabal as follows: if flag(BoundsChecks) cpp-options: -DVECTOR_BOUNDS_CHECKS Doesn't Cabal provide access to the flags that a package has been compiled with? It seems like it should and depending on the BoundsChecks flag would be cleaner than depending on a CPP symbol. Roman