[Haskell-cafe] Re: Microsoft's Singularity Project and Haskell

[Thomas DuBuisson]

On Sat, Jul 31, 2010 at 8:27 PM, wren ng thornton <wren at freegeek.org> wrote:
> Thomas DuBuisson wrote:
>>>
>>> And note that we wouldn't need unsafePerformIO for the FFI if all
>>> programs were made in Haskell ;).
>>
>> Perhaps that's true, though entirely unrealistic, in the application
>> world.  In the OS world you need access to machine registers and
>> special instructions (CR3 anyone? CP15?) which isn't built into any
>> language save assembly - for these FFI will always come in handy.
>>
>> Also, Haskell continues to have an unfortunate lack of primitives
>> suitable for casting types (ex: zero copy form a bytestring like
>> entity to Word32s).  In this realm FFI can outperform cleaner looking
>> code that must rely on individual byte reads.
>
> The FFI doesn't always require unsafePerformIO,

True.  I mis-read the previous e-mail as "we wouldn't need
unsafePerformIO OR (vs for) the FFI "  so please ignore that response
to a non-existent statement!