Re: Why is System.Posix.Error in unix?

Ian Lynagh wrote:

On Fri, Jul 20, 2007 at 05:20:36PM +0000, Aaron Denney wrote:

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On 2007-07-19, Ian Lynagh wrote:

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I get the feeling I must be missing something, but why is System.Posix.Error in the unix package? It looks to me like it just calls things in the base package, and it works on Windows as far as I can see: AIUI:

Because it's about the Posix "errno" interface, and nobody uses the posix subsystem of windows because it doesn't interact well with the GUI subsystem?

That might make sense to me, except the getErrno function that actually gets the errorno is in base:Foreign.C.Error, and it (well, under the non-hierarchical name CError) is specified in the FFI spec.

In fact, now I look more closely, it also defines a number of throwErrno* functions; it's only the throwErrnoPath* functions that are in unix:System.Posix.Error. This all seems very odd!

errno is defined by C99 (as well as POSIX), so it's reasonable to put errno-related stuff in Foreign.C.Error. When I needed to add some error-related functionality for the POSIX library, I didn't want to add extra stuff to Foreign.C.Error beyond what was specified in the FFI spec, so I added System.Posix.Error instead. This was just conservative; we could probably add throwErrnoPath and friends to Foreign.C.Error (with the usual proposal process). Cheers, Simon