[M3devel] what to do about file sizes being 32bits?

[Olaf Wagner]

Quoting Tony Hosking <hosking at cs.purdue.edu>:

> On 7 Jan 2010, at 08:52, Olaf Wagner wrote:
>
>> Well, I don't think that should be any practical problem right now,
>
>> shouldn't it? But 32 bit offsets have been overcome for years even
>> on 32 bit systems, so I definitely think we should keep the LONGINT
>> type and even try to incompatibly change the internal file length
>> type (with due care and consideration of course).
>
> I think I am now persuaded LONGINT should stay.  But, I don't   
> understand what "incompatibly change the internal file length
> type (with due care and consideration of course)" means?

I only just got round to reading all those mails.

I meant changing the file lengths and offsets in all our libraries,
like Rd/Wr. Basically what Jay has started on right away ;-)

I agree that this should be done in a feature branch though.
Changes should be reviewed.
Regression tests need to be run on all platforms.

And of course we should all more or less agree that we want to do that.
I think it has been a mistake that we haven't been able to support
long file sizes in a consistent way throughout our code. Of course this
problem will vanish in some years when everybody is using 64 bit platforms.
But for embedded programming for example 32 bit processors may remain
useful and in use much longer.

I'm not sure if we should support assignability between INTEGER and
LONGINT, as Rodney's original proposal did. Probably yes, but I must
admit that I've been too little engaged in language theory for years now
so that I cannot really oversee the impacts.

Files with sizes larger than 4 GB get more and more common. Just think
of DVD images for example. And I don't think that it will be really
appreciated by users of M3 applications that they immediately crash
just because one has opened a directory browser based on the distributed
libraries :-)

Just my opinion of course. I don't really understand why you are so
drastically opposing LONGINT suddenly. Probably I haven't been able to
follow some of the arguments.

Olaf
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