[R6RS] `eqv?' on immutable records

[William D Clinger]

Kent wrote:
> 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.

It would be a much bigger deal for programmers.
With the semantic change you advocate, programmers
would have to be taught that the beta rule cannot
be used without lifting quoted constants outside
the redex.

All sorts of program transformations that Scheme
programmers currently take for granted would be
made more complex by the semantics you advocate.

Will