Scheme language standardization process
On 07/12/2013 07:01 AM, Andrew Robbins wrote: > This is a comment about > > http://trac.sacrideo.us/wg/wiki/ComparatorsCowan > > I noticed some issues and should like to make comments about this possible SRFI/module. > > General Issues: > It is my personal opinion that this module should be helpful to anyone involved in either total orders or partial orders, such as floating-point numbers (which > form a total order if you ignore NaNs and -0.0). One way of doing this would be to use an exception/condition to express a lack of total order, another would be > to return something other than -1, 0, 1 from the compare procedure (perhaps return +nan.0), which would violate the conditions for a compare procedure according > to this module as specified so far. I'm not sure what the best way to do this is, except to provide additional procedures for floating-point numbers, and not > handle partial orders in a general way. My intuition tells me that a general approach would be more valuable in the long term, than to special case floats. > Treating any and all partial orders that come along as special cases, just seems wrong to me. On floating point numbers it would make sense (to me anyway) to return -0.0 in the case of a comparison of +0 and -0, and return NaN in the case of any comparison involving NaNs. But that's just for floating point. I don't have any ideas about a general case for the comparison semantics of unordered pairs. Bear _______________________________________________ Scheme-reports mailing list Scheme-reports@x http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports