use Perl

• critic to the rescue (Score:1)

  by daxim (8218) on 2009.01.31 6:32 (#67137) Homepage Journal

  The problem of needing to localise special variables is discussed in http://perldoc.perl.org/perlobj.html#Destructors [perl.org].

  There is a P::C policy ErrorHandling::RequireCheckingReturnValueOfEval [cpan.org] that catches this programming mistake. Its documentation also offers an alternative approach where you don't need to mess with other people's destructors to make it work.

  package SomeClass;
  sub new {
      return bless \my $foo => __PACKAGE__;
  }
  
  sub DESTROY {
      eval {'resetting $@'};
  }
  
  package main;
  use strict;
  use warnings;
  
  if (
      eval {
          my $obj = SomeClass->new();
          die "Code Red!\n";
          1;
      }
  ) {
      print "Exception caught: $@\n";
  } else {
      print "No exception occurred\n";
  }

  Reply to This

  • Re: (Score:1)

    by davebaker (4482)

    Did you mean to say

    if (
        eval {
            my $obj = SomeClass->new();
            die "Code Red!\n";
            1;
        }
    ) {
        print "No exception occurred\n";
    } else {
        print "Exception caught: $@\n";
    }