NAME

Error::Return - Really return() from a try/catch-block

VERSION

version 1.110510

SYNOPSIS

    use Try::Tiny;
    use Error::Return;

    sub foo {
        # ...
        try {
            # ...
            # return() here doesn't do what you might think it does
            RETURN 'bar';  # this actually returns from foo()
            # ...
        } catch {
            warn "caught error [$_]\n";
        };
        # ...
    }

DESCRIPTION

This module provides a way to return from within try/catch blocks with the expected semantics.

FUNCTIONS

RETURN

A try/catch-block as provided by Try::Tiny looks like the kind of block you might use in a for-loop or an if/then/else statement. However, it is really an anonymous subroutine, so if you return() from a try-block or a catch-block, you don't really return from the parent subroutine.

Like return except that it doesn't just return to its upper scope but smashes right through it to the next-higher scope. Actually, it skips two scopes, because it has to return from the try() subroutine as well.

RETURN is automatically exported.

ALTERNATIVES

Without this module, if you really wanted to return from a try/catch-block's parent subroutine, you would have to resort to something like this:

    use Try::Tiny;

    sub foo {
        ...
        my $should_return;
        try {
            ...
            $should_return = 1;
            ...
        } catch {
            ...
            # if we caught an exception, we should probably set
            # $should_return as well...
            ...
        };
        return if $should_return;
        ...
    }

PERFORMANCE

This module uses Scope::Upper, so there is a performance impact. However, a benchmark has shown that if used with Try::Tiny, it only takes about 5% more time than using the unsightly code given in the "ALTERNATIVES" section above. That is because try/catch does quite a bit of work itself, so the additional performance impact by munging scopes is not overly severe.

INSTALLATION

See perlmodinstall for information and options on installing Perl modules.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests through the web interface at http://rt.cpan.org/Public/Dist/Display.html?Name=Error-Return.

AVAILABILITY

The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit http://www.perl.com/CPAN/ to find a CPAN site near you, or see http://search.cpan.org/dist/Error-Return/.

The development version lives at http://github.com/hanekomu/Error-Return and may be cloned from git://github.com/hanekomu/Error-Return.git. Instead of sending patches, please fork this project using the standard git and github infrastructure.

AUTHOR

Marcel Gruenauer <marcel@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2009 by Marcel Gruenauer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm Error::Return

perl -MCPAN -e shell
install Error::Return