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Re: Issue: LOAD-TIME-EVAL (Version 8)
- To: Gray@DSG.csc.ti.com
- Subject: Re: Issue: LOAD-TIME-EVAL (Version 8)
- From: Kent M Pitman <KMP@STONY-BROOK.SCRC.Symbolics.COM>
- Date: Wed, 25 Jan 89 15:45 EST
- Cc: email@example.com, Moon@STONY-BROOK.SCRC.Symbolics.COM, CL-Compiler@SAIL.STANFORD.EDU
- In-reply-to: <2810748378-9770893@Kelvin>
Date: Wed, 25 Jan 89 13:26:18 CST
From: David N Gray <Gray@DSG.csc.ti.com>
> > Alternatively, you might abandon the intuition and think about the
> > consequences of just using EQ of the LOAD-TIME-VALUE expression. Would
> > it be so bad?
> That's pretty much the alternative I mentioned above, I guess.
This looks like the only viable answer to me.
I can't parse the original sentence [by Moon?] above, so I can't know whether
to agree or disagree. Which intuition are we talking about abandoning:
Intuition #1: (DOTIMES (I 5) (PRINT (LOAD-TIME-VALUE (F))))
evaluates the LOAD-TIME-VALUE expression only once.
Intuition #2: (DOTIMES (I 5) (PRINT (EVAL '(LOAD-TIME-VALUE (F)))))
evaluates the LOAD-TIME-VALUE expression at least 5 times.
I'm reluctant to abandon intuition #2 because I fear that it will complicate
debugging tremendously. eg, if the dynamic state changes [eg, due to a bug
fix] such that (F) can return a new value but it keeps returning an old value
due to some hidden cache, I think the effects would be very frustrating.
I'm willing to relax intuition #1 because I can see that some interpreters
would have too hard a time dealing with it. Nevertheless, I'd like to have
an implementation hint suggesting that the intuition be supported where
Given that intuition #1 is relaxed, I don't see the difficulty in supporting