Pointer value representation in Algol68?

kgw@stiscan.com (Ken Walter)
8 Oct 2000 22:33:48 -0400

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Pointer value representation in Algol68? kgw@stiscan.com (2000-10-08)
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From: kgw@stiscan.com (Ken Walter)
Newsgroups: comp.compilers
Date: 8 Oct 2000 22:33:48 -0400
Organization: Solution Technology
Keywords: question, code, algol68

Algol68 has rules about "scope" of REF REF values
to prevent pointer "up" the stack to something deallocated.
I can not take a reference to a local variable
and pass it to a more global scope. (I thibk thats the word?)

Even when I pass both the source and destination objects
to another procedure.

This means at run time for:
rri := ri;
The scopes of rri and ri must be compared.
If both are parameters then they must carry their scope information
with them.
I can not see how this can be done using a single "word"
as someone indicated many weeks ago in this group.

As I see it there are two "words", one for the pointer and one for the
"stack frame scope identifier".

Ken Walter WEEKDAY

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