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Postings from August 2012
* Ricardo Signes <perl.p5p@rjbs.manxome.org> [2012-08-25T08:07:40]
> > my $reading = Interval->new($raw_data, plus_minus=>$uncertainty);
> >
> > if ($reading ~~ 0) {...}
> >
> > # i.e. want Interval's overloading, not a numeric match against
> > # $reading object's address
>
> No, we want the same as C< $reading == 0 >, which can be done with current
> overloading. (In fact, which is done in my own Number::Tolerant for just this
> means.)
Another counterexample, harkening somewhat back to the one of the much earlier
examples from Damian.
for (@input) {
when (0) { warn "can't divide by zero" }
say $total / $_;
}
Seems safe, right? Well, if (similar to David Golden's "Error" example) an
element of @input wants to "force" stringwise matching against the zero and its
dual-var-ish string representation, even though there is 0+ overloading, then
this will explode. (In David's example, it wanted to force numification on
itself despite being matched against a string-function-using test; I have only
reversed the scenario.)
Again: I really think the test-writer (that is, the programmer chosing the
matching (not matched) operand) needs to be in control of the behavior of the
test.
--
rjbs
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