Per Bothner scripsit: > What should be the result of (infinite? +nan.0+inf.0i)? The report > says #t but that seems undesirable, because it would mean that > finite?/infinite?/nan? would no longer be a partitioning of the > complex numbers,
It never has been. If you look at R6RS, you'll see that these predicates are defined on real numbers only; the extension to complex numbers is new in R7RS. The WG decided that the convention that a partly-infinite complex number is an infinity and that a partly-NaN complex number is a NaN was more important than extending the trichotomy. There was some sentiment for declaring that any complex operation that generated a partial NaN should generate a NaN, pure and simple, but there were strong objections from the users of complex numbers, who expected to be able to extract meaningful results from a partial NaN. -- Winter: MIT, John Cowan Keio, INRIA, [email protected] Issue lots of Drafts. http://www.ccil.org/~cowan So much more to understand! Might simplicity return? (A "tanka", or extended haiku) _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
