I have another custom approach:
sub new {
my ($thing) = @_ ;
my $class = ( ref($thing) or $thing ) ;
my $self = bless({}, $class) ;
$self->{'errMsg'} = "";
# module user can set this e.g. to sub { carp($_[0]->{'errMsg'}) }
+ or something:
$self->{'errHandler'};
return $self ;
}
# Sets an error message, calls the error Handler, always returns undef
sub raiseError {
my ($self, $string) = @_;
$self->{'errMsg'} = $string;
&{$self->{'errHandler'}}($self) if $self->{'errHandler'};
return;
}
# returns error message and resets it to ""
sub error {
my ($self) = @_;
my $msg = $self->{'errMsg'};
$self->{'errMsg'} = "";
return $msg;
}
# ...
sub foo {
my ($self) = @_;
# do stuff
if ($trouble) {
return raiseError("foo: cannot do thisandthat");
}
# no error:
# make sure to return true-evaluating or at least non-undef value
return 1;
}
This way the module user can still use idioms like
$O->foo() or die "could not blabla: ".$O->error();
Users can still set the error handler to croak() if they wish. This could be extended ad nauseam: $debug switches, $exec_handler switch, method to get errMsg without resetting it -- you name it. I should probably put it in its own module, too, and inherit from that. I'm still not sure how to escalate errors when one method calls another. Maybe simply
sub bar {
my ($self) = @_;
foo() or return raiseError("bar failed to rhubarb: ".$self->error(
+));
return 1;
}
# ...
$O->bar() or die "could not blabla: ".$O->error();
# "could not blabla: bar failed to rhubarb: foo: could not do thisandt
+hat"
