NAME

Sub::ForceEval - runtime cluck if a dying subrutine is not eval-ed.

VERSION

This document describes Sub::ForceEval version 0.0.1

SYNOPSIS

    use Sub::ForceEval;

    # if any call to foo dies an eval will be added 
    # at runtime if there isn't already one on the
    # stack.

    sub foo :ForceEval
    {
       ...
    }


    # a bare call to foo() in the main code will cluck
    # about having no eval on the stack and get wrapped
    # on the fly if anything in it dies.

    foo();

    # this works, however, since foo can find that
    # bletch was called from within an eval.

    eval { bletch() };

    sub bletch { bar() }

    sub bar { foo() }

DESCRIPTION

Subroutines that are marked with the ForceEval attribute check at runtime if there is an eval on the stack when the call dies. If there is an eval on the stack then the die is propagated to it via die $@; if not then cluck (see Carp) is called and the die is trapped.

The stack is only checked if something dies, so there is relatively little overhead in using the attribute.

Note that this inludes anything that dies for any reason even if the death is not intended as an OO 'exception'. This can be helpful for long-lived processes that need to ensure survival. It can also be handy for subs that call modules which use Fatal: all of the fatalities can be guaranteed to be gracefully handled.

INTERFACE

Use the module and add the :ForceEval attribute to a subroutine:

    use Sub::ForceEval;

    sub foo :ForceEval { ...}

DIAGNOSTICS

"Missing eval for '$name'", $@

An :ForceEval subroutine was called from a context where exceptions would not be caught by any surrounding eval. This uses Carp::cluck to complain about the fact and keeps going.

CONFIGURATION AND ENVIRONMENT

Sub::ForceEval requires no configuration files or environment variables.

DEPENDENCIES

  strict

  Carp

  Symbol

  version

  Attribute::Handlers 

INCOMPATIBILITIES

None reported.

BUGS AND LIMITATIONS

No bugs have been reported.

This is nearly impossible to test since detecting that the module incorrectly detected an existing eval requires running it in an eval...

Please report any bugs or feature requests to bug-sub-ForceEval@rt.cpan.org, or through the web interface at http://rt.cpan.org.

AUTHORS

Steven Lembark <lembark@wrkhors.com> Damian Conway

LICENCE AND COPYRIGHT

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

cpanm Sub::ForceEval

perl -MCPAN -e shell
install Sub::ForceEval