[r6rs-discuss] Re: [Formal] eq?/eqv? misbehave around NaNs

From: Abdulaziz Ghuloum <aghuloum>
Date: Thu Nov 23 17:34:26 2006

On Nov 23, 2006, at 4:07 PM, Per Bothner wrote:
>
> I think it is important to not break:
> (eq? x x) implies (eqv? x x)
> and:
> (let ((x expr)) (eq? x x))

These are not axioms in Scheme. They hold for Eq-comparable things
(mutable objects and closures, iirc). For numbers, eq? is
meaningless and therefore cannot imply anything.

For example, the expressions
(let ([x expr])
   (or (not (eq? x x)) (eq? x x)))

may return #f in some implementations (under special celestial
alignment).

Aziz,,,
Received on Thu Nov 23 2006 - 17:34:06 UTC