Official definition of call-by-value (Re: Finding the instance reference...)

[Steven D'Aprano]

On Sun, 23 Nov 2008 09:24:05 -0600, Derek Martin wrote:

> On Tue, Nov 18, 2008 at 09:23:30AM +0000, Steven D'Aprano wrote:
>> > How I can answer the question, "are the objects a and b the same or
>> > different"? I can look at every aspect of each object, looking for
>> > something that is different.
>> 
>> Well, sure, if you care *that much* about potentially trivial aspects.
>> I have a ten dollar note with a spec of dirt on one corner, and a ten
>> dollar note with a slightly larger spec of dirt on a different corner.
>> I'd agree with you that they are not "the same" in every aspect, but
>> they're the same in every way I care about.
> 
> It's trivial to show that this is not necessarily the case -- you just
> haven't thought of all the ways in which a difference might matter to
> you..
> 
> Suppose that one of the 10-dollar bills had a serial number which was
> never printed by the government (i.e. it is counterfiet).  Are they
> still the same in every way that you care about?

Derek, I realise that this is the Thread From Hell That Just Won't Die, 
but you really should make an effort to read all of it before jumping 
into the middle of it. You're not saying anything that I haven't already 
said. I'm happy to have reasoned support from others, but you're arguing 
with the wrong guy: I've been saying that "the same value" of two objects 
is context-dependent since earlier in this thread than you have.

And let me repeat Steve Holden's comment about unnecessarily quoting text 
you aren't responding to. (Approximately) 260 lines of dead text at the 
end of your post is excessive and rude. Please trim it in the future.

[...]


-- 
Steven