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Postings from August 2012
On Fri, Aug 24, 2012 at 09:40:35AM +1000, Damian Conway wrote:
> Leon Timmermans wrote:
>
> > I suspect in practice junctions may be the only use-case for it. I
> > can't think of any other use-case.
>
> Interesting. I can think of numerous other use-cases...
>
> 1. In this very thread we've already seen Robert Sedlacek excellent
> suggestion for type objects, for which I've already demonstrated
> several possible ~~-overloadings.
>
> 2. I'd also very much like to be able to overload ~~ for
> Regexp::Grammar objects.
>
> 3. And I can imagine that a similar overloading of ~~ for objects
> encapsulating Marpa grammars would be of even greater value.
>
> 4. The bioinformatics people might well like to be able to overload
> ~~ to perform searches or alignments on objects representing DNA
> and RNA sequences.
>
> 5. I can also imagine ~~ overloaded to support Query objects:
>
> if ($db ~~ $query) {...}
>
> 6. And I already have plans to allow InputConstraint objects, for
> abstracting input filtering using my IO::Prompter module, by
> being internally smartmatched:
>
> my $input = prompt 'Enter a number', must=>$constraint_obj;
None of these use cases are for overloaded objects on the lhs of the
smart match, which was the subject here. What other non-junction use
cases are there for that? (Note that equality operators (.=, etc)
already don't check overloading on their lhs, so this behavior isn't
unprecedented.)
-doy
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