On 3 Oct 2011, at 04:08, Aubrey Jaffer wrote: > | > Shouldn't the predicates REAL? and COMPLEX? implement the > | > mathematical semantics for which they are named? > | > | ... There are two reasonable sets of semantics here, and by > | providing two sets of procedures we can support both. By adding an > | "exact-complex" feature, a program that depends on exact complex > | numbers can rely on being run only on an implementation that > | supports them. > > The terms integer, rational, real, and complex are too few to > adequately describe all the possible numeric Scheme types. Rather > than misuse basic mathematical terms, coin new names for the numeric > types which don't match the mathematical types.
In math, there are two distinct copies of the integers in play: the ring of integers Z, and the copy of it embedded into the field Q of rational numbers. A similar thing happens with real and complex numbers. One could think of having that model in a computer program. Hans _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
