Re: issue LOAD-TIME-EVAL

[Jeff Dalton <jeff%aiai.edinburgh.ac.uk@NSS.Cs.Ucl.AC.UK>]

> At least one "wizard" at Lucid was thoroughly confused by the
>     (CONS #1=(LOAD-TIME-VALUE (COMPUTE-IT)) #1#)
> example.  Perhaps it needs to be fleshed out.
> 
> I liked Aaron Larson's comment on the matter:
>    "I was under the impression that the only loophole permitting the 
>     compiler to copy/substitute otherwise non EQ forms was with regard 
>     to QUOTE."
> That is, one might conceivable think of coalescing the two calls to
> LOAD-TIME-VALUE  because of a sort of similarity to QUOTE.

I don't understand this remark.  Aaron seems to be say that only
QUOTE allows EQ things to become non-EQ, and you seem to say that 
only QUOTE allows non-EQ things to become EQ.  
  But as
> Aaron further noted, the compiler cannot reduce the calls to CONS
> in the structurally isomorphic form:
>    (EQ #1=(CONS 'A 'B) #1#)
> So why should LOAD-TIME-VALUE be any different.
> 
> 
> Also your comment about constraints on the interpreter could be helpful:
>   ". . . but it's not legitimate to cache LOAD-TIME-VALUE forms and 
>     resulting values and do a lookup based on EQness of source code 
>     expressions."
> 
> 
> -- JonL --
> 
>