Re: New release of SRFI 114 with implementation John Cowan 08 Dec 2013 03:13 UTC
Kevin Wortman scripsit: > I presume that the convenience behavior when compare or hash are #f, is > provided to support objects that are orderable or hashable but not both. > This is reasonable, but it seems like there needs to be some method of > introspection to determine whether one of a comparator's procedures > is effectively missing. A hash table may want to raise an error when > given a non-hashing comparator, for instance. You are apparently looking at an older version of the SRFI document. The current version has the predicates `comparator-comparison-procedure?` and `comparator-hash-function?` for this very purpose. > Binary comparison predicates > Chain (multiple argument) comparison predicates > > Why not have only the chain predicates, with the short names used for > the current "Binary comparison predicates"? This is now the case. > Min/max comparison predicates > > When multiple arguments are tied for minimum/maximum, which one is > returned? This matters when the minimal/maximal objects are equal > according to the comparator but not according to eqv?. An excellent point. The current implementation produces the last minimal/maximal argument; are there any objections to making this the standard? -- Being understandable rather than obscurantist poses certain risks, in that one's opinions are clear and therefore | John Cowan falsifiable in the light of new data, but it has the | xxxxxx@ccil.org advantage of encouraging feedback from others. --James A. Matisoff