Proposal: Bounded instance for IntSet (ticket #1953)
dbenbenn at gmail.com
Mon Dec 3 10:22:48 EST 2007
On 12/3/07, Yitzchak Gale <gale at sefer.org> wrote:
> In this case, the Ord instance is not really natural; it is defined
> for technical reasons for use by the library itself (and its
> friends). The library has no need for a Bounded instance, so why
> should we prevent people from defining one for some other purpose?
Note that in one sense, people are already prevented from defining a
different Bounded instance. Any Bounded instance other than the one
suggested in this proposal would fail to obey the axioms of the
Bounded class. In other words, there is a unique largest element, and
a unique smallest element, an no one can legitimately define a
different Bounded instance.
Given that the Bounded instance is uniquely defined, I think it is
more convenient to have it defined by the library than to have to
manually define it in every program that uses it.
More information about the Libraries