Perl Module Object - Return fail/success with a fault string

jhyland87 has asked for the wisdom of the Perl Monks concerning the following question:

So I am creating my first perl module, (atleast my first advanced one thats more than a few lines of code), and hope to submit it to CPAN, so id like to get it working perfectly

Right now, im trying to get the subroutines to return both a standard return code (0 or non 0), with a "fault code"

I guess heres an example of the current code (not really, but this is basically an example of what I have, in the relative aspect)

File: ./Module/Test.pm

package Test.pm;

sub new
{
    my ($self, $value) = (@_);
    my @return

    %return = ("code" => 1, "fault" => "You didnt even send a value to
+ me!\n") if (!$value);
    %return = ("code" => 0, "value" => "Cool, you sent me $value\n") i
+f ($value);
    
}
[download]

Test File: ./test.pl

use Module::Test;

$test = Module::Test->new();

die($test->{'fault'}) if (!$test);

# Didn't die
print $test->{'value'} if ($test);
[download]

Kinda get what I mean? Return both an exit code, as well as a comment that I can reference? THE ABOVE CODE IS NOT TESTED!! In fact, I doubt it works, so don't diagnose that, im just trying to get the idea of my goal to you through a code example...

Thanks in advance! (and yes, I googled it)

Comment on Perl Module Object - Return fail/success with a fault string Select or Download Code

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Re: Perl Module Object - Return fail/success with a fault string by Corion (Patriarch) on Jan 03, 2012 at 09:52 UTC
What you want is certainly possible, but your code in `Module::Test` is not how you construct objects (or "objects"). Please have a look at bless or one of the object tutorials. If your objects are merely collections of data, just return an unblessed hash reference: `sub new { ... return \%return };` [download]	[reply] [d/l] [select]
Re^2: Perl Module Object - Return fail/success with a fault string by jhyland87 (Sexton) on Jan 03, 2012 at 16:56 UTC
ok, so bless the hash and then return it, got it. How would I structure it though so that perl sees the exit code within the hash?	[reply]
Re^3: Perl Module Object - Return fail/success with a fault string by Corion (Patriarch) on Jan 03, 2012 at 17:08 UTC
What do you mean by that? Do you ask how to set a key in your hash? I think it would help me if you show what you got and show what you want.	[reply]
Re^4: Perl Module Object - Return fail/success with a fault string by jhyland87 (Sexton) on Jan 03, 2012 at 19:09 UTC
Re^5: Perl Module Object - Return fail/success with a fault string by Corion (Patriarch) on Jan 03, 2012 at 21:10 UTC
Re^3: Perl Module Object - Return fail/success with a fault string by ~~David~~ (Hermit) on Jan 03, 2012 at 17:08 UTC
I would recommend not returning an error code or value. If you don't get the data you need, a good option is to carp/warn and return undef, or die/croak ( depending on whatever is appropriate ).	[reply]
Re: Perl Module Object - Return fail/success with a fault string by BrowserUk (Patriarch) on Jan 03, 2012 at 18:15 UTC
I think this is what you are looking for: `use Scalar::Util qw[ dualvar ];; sub alwaysFails { return dualvar -123, 'Some text to explain the error'; } $rv = alwaysFails();; print "Sub failed with error: $rv" if $rv != 0;; Sub failed with error: Some text to explain the error` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply] [d/l]
Re^2: Perl Module Object - Return fail/success with a fault string by jhyland87 (Sexton) on Jan 03, 2012 at 19:39 UTC
Kinda? but not really, the below doesn't seem to work `print "Sub failed with error: $rv" if (!$rv);` [download] Meaning that it doesn't actually return a fail code, just a value of != 0	[reply] [d/l]
Re^3: Perl Module Object - Return fail/success with a fault string by BrowserUk (Patriarch) on Jan 03, 2012 at 19:56 UTC
The problem is that `!` does not provide a numeric context. `use Scalar::Util qw[ dualvar ];; sub alwaysFails { return dualvar 0, 'Some text to explain the error'; +};; $rv = alwaysFails();; print "Sub failed with error: $rv" if !$rv;;` [download] If you want 0 to stand for failed, you'd need to use a test that does provide a numeric context. Eg. `print "Sub failed with error: $rv" if ! 0+$rv;; Sub failed with error: Some text to explain the error print "Sub failed with error: $rv" if ~$rv;; Sub failed with error: Some text to explain the error print "Sub failed with error: $rv" if $rv == 0;; Sub failed with error: Some text to explain the error` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply] [d/l] [select]