use 5.006;
# ABSTRACT: minimal try/catch with proper preservation of $@
-our $VERSION = '0.23';
+our $VERSION = '0.27';
use strict;
use warnings;
*_HAS_SUBNAME = ($su || $sn) ? sub(){1} : sub(){0};
}
+my %_finally_guards;
+
# Need to prototype as @ not $$ because of the way Perl evaluates the prototype.
# Keeping it at $$ means you only ever get 1 sub because we need to eval in a list
# context & not a scalar one
_subname("${caller}::try {...} " => $try)
if _HAS_SUBNAME;
+ # set up scope guards to invoke the finally blocks at the end.
+ # this should really be a function scope lexical variable instead of
+ # file scope + local but that causes issues with perls < 5.20 due to
+ # perl rt#119311
+ local $_finally_guards{guards} = [
+ map { Try::Tiny::ScopeGuard->_new($_) }
+ @finally
+ ];
+
# save the value of $@ so we can set $@ back to it in the beginning of the eval
# and restore $@ after the eval finishes
my $prev_error = $@;
$error = $@;
$@ = $prev_error;
- # set up a scope guard to invoke the finally block at the end
- my @guards =
- map { Try::Tiny::ScopeGuard->_new($_, $failed ? $error : ()) }
- @finally;
-
# at this point $failed contains a true value if the eval died, even if some
# destructor overwrote $@ as the eval was unwinding.
if ( $failed ) {
+ # pass $error to the finally blocks
+ push @$_, $error for @{$_finally_guards{guards}};
+
# if we got an error, invoke the catch block.
if ( $catch ) {
# This works like given($error), but is backwards compatible and
Using Perl 5.10 you can use L<perlsyn/"Switch statements">.
+=for stopwords topicalizer
+
The C<catch> block is invoked in a topicalizer context (like a C<given> block),
but note that you can't return a useful value from C<catch> using the C<when>
blocks without an explicit C<return>.
=item *
C<@_> is not available within the C<try> block, so you need to copy your
-arglist. In case you want to work with argument values directly via C<@_>
+argument list. In case you want to work with argument values directly via C<@_>
aliasing (i.e. allow C<$_[1] = "foo">), you need to pass C<@_> by reference:
sub foo {
will not report this when using full stack traces, though, because
C<%Carp::Internal> is used. This lack of magic is considered a feature.
+=for stopwords unhygienically
+
=item *
The value of C<$_> in the C<catch> block is not guaranteed to be the value of
the exception thrown (C<$@>) in the C<try> block. There is no safe way to
-ensure this, since C<eval> may be used unhygenically in destructors. The only
+ensure this, since C<eval> may be used unhygienically in destructors. The only
guarantee is that the C<catch> will be called if an exception is thrown.
=item *
Note that this behavior was changed once again in L<Perl5 version 18
|https://metacpan.org/module/perldelta#given-now-aliases-the-global-_>.
-However, since the entirety of lexical C<$_> is now L<considired experimental
+However, since the entirety of lexical C<$_> is now L<considered experimental
|https://metacpan.org/module/perldelta#Lexical-_-is-now-experimental>, it
is unclear whether the new version 18 behavior is final.
L<http://web.archive.org/web/20100305133605/http://nothingmuch.woobling.org/talks/yapc_asia_2009/try_tiny.yml>
-=head1 VERSION CONTROL
-
-L<http://github.com/doy/try-tiny/>
-
=cut
-