Re: [Qemu-devel] Use a hex string

[Jamie Lokier <jamie@shareable.org>]

Anthony Liguori wrote:
> On 05/23/2011 06:02 PM, Jamie Lokier wrote:
> >Richard W.M. Jones wrote:
> >>The problem is to be able to send 64 bit memory and disk offsets
> >>faithfully.  This doesn't just fail to solve the problem, it's
> >>actually going to make it a whole lot worse.
> >
> >Such offsets would be so much more readable in hexadecimal.
> >
> >So why not use a string "0xffff800012340000" instead?
> 
> This doesn't change the fundamental issue here.  Javascript's internal 
> representation for integers isn't 2s compliment, but IEEE794.  This 
> means the expectations about how truncation/overflow is handled is 
> fundamentally different.

No, the point is it's a string so Javascript numerics doesn't come
into it, no overflow, no truncation, no arithmetic.  Every program
that wants to handle them handles them as a *string-valued attribute*
externally, and whatever representation it needs for a particular
attribute internally.  (Just as enum values are represented with
strings too).

In the unlikely event that someone wants to do arithmetic on these
values *in actual Javascript*, it'll be tricky for them, but the
representation doesn't have much to do with that.

-- Jamie