Explanation of list reference

[Chris Angelico]

On Sat, Feb 15, 2014 at 5:07 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> Nice point!
> I earlier talked of the macro problems of identity, viz across machines.
> You are bringing up a more 'micro' angle, viz gc.
> An even more micro (or lower level) example would be the mismatch between
> physical and virtual memory, dram and cache etc etc.
> Is memory such a clear concept?
>
> Just different examples to show that object identity is anything but
> straightforward

Not really; they just show that object identity is nothing to do with
memory location. An object is itself, and is not anything else, and
neither of those truisms has anything to do with memory. I could
implement Python using a pencil and paper, using physical pieces of
string to create references; if a gust of wind blows all the paper
around, it won't change anything. (Though it might be a problem if I
have any weak references...) You could walk up to me and look at my
pieces of paper, and you'll know if two strings are linking to the
same paper; it's obvious that that paper is the same thing as itself.

ChrisA