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.