in reply to How to return an appropriate error from module?

The interface you asked about is provided by: 
sub validate_phone_num {
   return eval {
      /^$/ or die "No number\n";
      ...
      $cleaned_up_num
   };
}

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Re^2: How to return an appropriate error from module?
by zrajm (Beadle) on Mar 06, 2009 at 14:22 UTC
    I like this idea.

    Is there any rule/praxis for or against setting $@ inside my modules or subroutines -- as a way of returning error messages?

    If using above example as a guide, would the following module be considered to be "kosher" perl? 

    package Phone;
sub prettify {
    local ($_) = @_;
    return eval {
        /^$/ and die "No number\n";
        # do something to modify $_ here
        $_;
    };
}

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    In my main program this could then be called using: 

    my $pretty_number = Phone::prettify($number)
if (not defined($pretty_number)) {
    # e.g. insert message $@ into web page output
}

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      It is a bit odd. Why not let the exception propagate? 
      package Phone;
sub prettify {
    local ($_) = @_;
    /^$/ and die "No number\n";
    # do something to modify $_ here
    $_;
}

      [download]
      my ($pretty_number) = eval { Phone::prettify($number) }
   or do { ...insert message $@ into web page output...
           ...exit/return/next/etc...
         };

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