[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: New release of SRFI 114 with implementation



On 12/03/2013 08:16 PM, John Cowan wrote:
> I finally finished writing the sample implementation of SRFI 114,
> Comparators, with the exception of the tests.

As others have said, this is a useful and clean proposal. A few minor
comments:

(make-comparator type-test equality compare hash)

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.

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"?

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?.

Kevin Wortman