Patch with new API for get/setsockopt

[Matthew Danish]

On Sat, Sep 08, 2007 at 09:03:45PM -0700, Bryan O'Sullivan wrote:
> I would prefer to see the API changed to associate the type of a value 
> with the name of its constructor, like this:
> 
> data SocketOption = DontRoute Bool
>                   | TimeToLive Int64
>                   | ...
> 
> One could still pass values of this type into getSocketOption by filling 
> out the arguments to a constructor with any value, including undefined. 
>  There's already ample precedent for this, in the form of 
> Data.Storable's sizeOf.
> 
> This presents a safer statically checkable interface, while remaining in 
> the bounds of H98.

I thought of this, but didn't go this way because I did not want to
change the existing SocketOption type.  There's also some argument
that providing such a type is higher-level than the Network.Socket
library, since everything else is pretty much as unforgiving as C.
The point of this patch was to bring the Haskell API to
getsockopt/setsockopt at least to the level of the C API (which
exploits weak typing).

I would much prefer a nicer interface, of course, but I am not sure
that it should be part of Network.Socket.  I was originally planning
to write something with type families, but then realized that this had
to run in Hugs as well.

-- 
-- Matthew Danish -- user: mrd domain: cmu.edu
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