Re: Endianness independance

[Jeffrey Carter <jrcarter@acm.org>]

Stephen Leake wrote:
> Jeffrey Carter <jrcarter@acm.org> writes:
> 
>>You can make this system independent by using
>>System.Default_Bit_Order, which, thanks to an AI (I don't remember
>>which, but you can look it up) is static.
> 
> What do you mean by "system independent"? This code is already
> portable without change across targets that differ in endianness;
> that's whay I mean by "system independent".
> 
> Exactly how would I use System.Default_Bit_Order for this purpose?
> 
> I can check that System.Default_Bit_Order has a particular value, and
> only provide a rep clause that is correct for that value. But I don't
> see how to use System.Default_Bit_Order in the rep clause; it does not
> provide enough information.

You said your package was "system dependent" because you have to change 
it for different platforms. Using Default_Bit_Order you can make it work 
without change on all platforms.

You can use 'Pos of Default_Bit_Order to calculate all of the named 
numbers in your package. You can then continue to use your package as 
before, but without changing it when you change platforms.

-- 
Jeff Carter
"Perfidious English mouse-dropping hoarders."
Monty Python & the Holy Grail