[R6RS] `eqv?' on immutable records

Michael Sperber sperber at informatik.uni-tuebingen.de
Tue May 15 05:38:38 EDT 2007


"R. Kent Dybvig" <dyb at cs.indiana.edu> writes:

> I think it's confusing if the immutability of a pair or other normally
> mutable object has some effect on the behavior of eqv?.  Indeed, I prefer
> that immutability of a pair or other normally mutable object affect only
> whether portable programs are permitted to mutate it.  It's not a big deal
> for a compiler that unboxes constants to (a) avoid doing so if a constant
> can reach eqv?, (b) maintain both boxed and unboxed forms when necessary,
> or (c) recover eqv?  semantics for unboxed constants by commonizing eq? 
> substructures of constants in the final output.

This means you'd prefer this:

(eqv? '(a) '(a)) => #f

Right?  (Currently, we have => unspecified.)

-- 
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla



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