Dear monks,
I am trying to understand how to use Exception::Class in a large-ish multimodule application. As part of the set of modules I made one package where I am planning to define all exceptions, i.e.:
package Bio::Phylo::Exceptions;
use Exception::Class (
'Bio::Phylo::Exceptions',
'Bio::Phylo::Exceptions::BadNumber' =>
{ isa => 'Bio::Phylo::Exceptions' },
'Bio::Phylo::Exceptions::BadString' =>
{ isa => 'Bio::Phylo::Exceptions' },
'Bio::Phylo::Exceptions::BadFormat' =>
{ isa => 'Bio::Phylo::Exceptions' },
'Bio::Phylo::Exceptions::ObjectMismatch' =>
{ isa => 'Bio::Phylo::Exceptions' }
);
1;
So then, elsewhere in the modules, there might be OO getters and setters like this:
use Scalar::Util qw(looks_like_number);
sub set_number {
my ( $self, $number ) = @_;
looks_like_number $number
? $self->{'NUMBER'} = $number
: Bio::Phylo::Exceptions::BadNumber->throw(error => 'bad number');
}
And then the user has to go through a contortion like:
# try
eval { $obj->set_number(sdf7897) };
# catch
if (UNIVERSAL::isa($@,'Bio::Phylo::Exceptions::BadNumber')){
# do something
}
Is that how it works? Or are the exceptions caught inside the object methods?
Pardon my ignorance, but I've never worried about this before, and I wish to learn.
Thank you!
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