Re: Endianness independance

[Simon Wright <simon@pushface.org>]

amir@iae.nsk.su (Amir Yantimirov) writes:

> I think this sentence isn't true at least for 5 years already.
> Interoperability is so crucial that today where is no excuse for
> existance of hardware what don't support common data representation.

On the one side you have Intel. On the other SPARC and PowerPC (well,
as usually configured on eg iMacs). There isn't a common
representation; it's up to software to make sure of interoperability
when you need it.

> As you pointed in other thread this wasn't a goal when Ada was
> created. Contrary, such implicit "genericity" is a common trait of
> all older languages. And opposite, a newer languages as Java and C#
> exactly specify representation of integer and floating point types.
> This is a direct answer to common demand of developers.

I don't know about C#, but it's not obvious that its creators would
have been bothered about execution on non-Intel hardware.

It is not at all likely that a Java int has the same representation at
runtime on a PC as on an iBook. It would be painfully slow on one of
them (probably the PC!).

What you do get is support from the networking infrastructure (RMI?)
to convert the data to a common format "on the wire" and back to the
native format at the other end.

Where is "bit 0"? I always thought it was the least significant bit
(binary 1), but (depending on the programming/hardware conventions)
you may find it's the _most_ significant bit.


I do agree that, most of the time, what you need is for all this cruft
to be hidden. Every so often, though, it will creep out and bite you.