My point is that if you're wrapping in a try-block, you should be throwing exceptions, even something like Error::OK or the like. In fact, I wouldn't even call them exceptions, really. They're more like signals within the same process. Just because we use them 99.999% of the time to indicate an abnormal situation doesn't mean that this is what they should be limited to ...
------ We are the carpenters and bricklayers of the Information Age. Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement. Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified. | [reply] [Watch: Dir/Any] |
In the find() example, assuming that stored(), next() and first() can throw error exceptions, show me some simpler code using exceptions rather than multiple returns.
I've no objection to using exceptions for non-error conditions. I do it all the time :-)
However, I do have an objection to making my code more complex because of an arbitrary rule. Why should I not use return within a try block when it makes my code far easier to understand and maintain than the alternative? What is the downside?
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sub find {
my ($self, $search_item) = @_;
eval {
# skip expensive search if item not stored anywhere
throw Signal::Search::Not_Stored
unless $search_item->stored;
# otherwise do expensive search
$self->first;
while (my $item = $self->next) {
throw Signal::Search::Found
if $item == $search_item;
};
throw Signal::Search::Not_Found;
}; if ($@) {
my $e = $@;
# Do NOT handle Signals here. Those propagate back
# up to the caller who will handle them appropriately.
throw $e if $e->isa('Signal::Search');
... handle exceptions here ...
};
};
I would argue that you have three possible return codes - NOT_STORED, FOUND, NOT_FOUND, plus all the possible exceptions that can occur. Instead of trying to shoehorn your return codes into a C-like morass of constants and bit-vectors, use signalling exceptions! Heck, you can even include a reference to the found item in your Signal::Search::Found object, if you were so inclined. And, your code is self-commenting because you make a distinction between NOT_STORED and NOT_FOUND, in case the caller or reader cares. If they don't, they can explicitly treat the two cases the same, increasing the commenting.
------ We are the carpenters and bricklayers of the Information Age. Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement. Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified. | [reply] [Watch: Dir/Any] [d/l] |