Re: RM and abstract syntax trees

On Nov 1, 1:59 pm, Marshall <marshall.spi..._at_gmail.com> wrote:

> I mentioned previously that pointers are only meaningful or
> functional within the context of a specific, typically non-portable
> address space. Without the address space, pointers might as
> well be random numbers. So if you are going to pack up some
> data and move it from, say, one machine to another, you
> have to go through all sorts of contortions to preserve some
> semblance of pointer semantics. And as anyone who's dug
> through the code for Java serialization, this is quite ugly
> and error prone. Whereas if you want to copy some
> relations from one place to another no transformations of
> any kind are necessary. Which rather highlights how the
> relational form is a logical form, and not a physical form.

Here's another perspective on the pointer analogy I've been making...

In an RM representation of an AST, those arbitrary node identifiers aren't meaningless in the context of the DB, in the same fashion that pointer values aren't meaningless in the associated memory address space.

It seems to me that it's reasonable to say that the DB is *defining* a local address space, and paraphrasing your comment above : without the address space, node identifiers might as well be random numbers. Received on Fri Nov 02 2007 - 03:50:23 CET