Mark H Weaver scripsit: > My point is that your ComplexRepresentation page states that Guile and > Racket do not support complex numbers of mixed exactness, but that's not > quite true. There is one important special case of mixed exactness that > *is* supported in Guile, Racket, Ikarus, and perhaps others.
In that case, *every* Scheme that supports inexact reals at all, a priori supports complex numbers of mixed exactness such that the imag-part is 0. This is true a priori, and so doesn't belong on the ImplementationContrast pages, which are about empirical differences between Schemes. Or is what you mean that some Schemes, when asked for the imag-part of 2.0, may return 0.0 rather than 0? I can check for that possibility when I'm back home. > Another test that would be worthwhile is this: > > (list (eqv? +0.0 -0.0) > (eqv? (make-rectangular +0.0 1.0) > (make-rectangular -0.0 1.0)) > (eqv? (make-rectangular 1.0 +0.0) > (make-rectangular 1.0 -0.0)) > > I wouldn't be surprised if some Schemes distinguish signed zeroes in the > real part but not in the imaginary part. If an implementation discards > inexact zero imaginary parts, then it probably discards the sign as well > as the exactness. I'll try that. -- Dream projects long deferred John Cowan <[email protected]> usually bite the wax tadpole. http://www.ccil.org/~cowan --James Lileks _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
