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Re: issue QUOTE-MAY-COPY, version 3
- To: email@example.com
- Subject: Re: issue QUOTE-MAY-COPY, version 3
- From: cperdue@Sun.COM (Cris Perdue)
- Date: Tue, 3 Jan 89 14:08:41 PST
I am opposed to all of the proposals offered in their current
CLtL takes a simple, useful approach to this problem. The idea
that QUOTE cannot reasonably operate as defined in CLtL is incorrect,
though it appears desirable to explain somewhere the "copying"
effects that compile-file may have on constants.
To say that QUOTE copies in existing implementations is to
imply that a lot of copying might happen that never actually
happens. COMPILE-FILE followed by LOAD effectively copies,
and in KCL, COMPILE effectively makes a copy, but not QUOTE.
I object strongly to suggestions that QUOTE copies in existing
practice, at least existing practice as I know it. Among other things,
this skews the entire discussion. It also limits the set of datatypes
that can be QUOTEd, because the equivalence defined in
CONSTANT-COMPILABLE-TYPES does not support all datatypes.
It is possible for QUOTE or a garbage collector to copy
constants into readonly storage, but I think that rationale is
different from supporting existing practice. With that rationale
I might support something like QUOTE-MAY-COPY:ALWAYS, but I think
it would be questionable whether the equivalence defined in
CONSTANT-COMPILABLE-TYPES is sufficient. A version
that applies to all objects might be advisable as the equivalence
maintained by QUOTE.