[plt-scheme] When does eqv? differ from eq? , from equal?

> What I meant was, I only use eq? when I really mean "pointer equality"
> -- generally for comparing two mutable structures, though I also use
> it for symbols.

This is an interesting point. So, does eq? not break the abstraction
provided by functional languages? I think we have lost a battle if
functional programmers are thinking in terms of pointers! IMHO, this
should never be the case. I know, of course, there is always the
efficiency argument, but that needs to be supported by strong
empirical evidence indicating that it makes a tremendous difference in
performance. Anything that forces functional programmers to think
about the implementation details is a likely candidate to be left out
in the future (one would hope!), no?

-- 

Cheers,

Marco