10 indirect - Lexically warn about using the indirect object syntax.
27 my $x = new Apple 1, 2, 3; # warns
30 my $y = new Pear; # ok
32 no indirect hook => sub { die "You really wanted $_[0]\->$_[1] at $_[2]:$_[3]" };
33 my $z = new Pineapple 'fresh'; # croaks 'You really wanted Pineapple->new at blurp.pm:13'
39 if (defied $foo) { ... } # croaks, note the typo
41 # From the command-line
42 perl -M-indirect -e 'my $x = new Banana;' # warns
44 # Or each time perl is ran
45 export PERL5OPT="-M-indirect"
46 perl -e 'my $y = new Coconut;' # warns
50 When enabled (or disabled as some may prefer to say, since you actually turn it on by calling C<no indirect>), this pragma warns about indirect object syntax constructs that may have slipped into your code.
51 This syntax is now considered harmful, since its parsing has many quirks and its use is error prone (when C<swoosh> isn't defined, C<swoosh $x> actually compiles to C<< $x->swoosh >>).
53 It currently does not warn for core functions (C<print>, C<say>, C<exec> or C<system>).
54 This may change in the future, or may be added as optional features that would be enabled by passing options to C<unimport>.
56 This module is B<not> a source filter.
62 XSLoader::load(__PACKAGE__, $VERSION);
67 =head2 C<< unimport [ hook => $hook | ':fatal' ] >>
69 Magically called when C<no indirect @opts> is encountered.
71 The policy to apply depends on what is first found in C<@opts> :
77 If it's the string C<':fatal'>, the compilation will croak on the first indirect syntax met.
81 If the key/value pair C<< hook => $hook >> comes first, C<$hook> will be called for each error with a string representation of the object as C<$_[0]>, the method name as C<$_[1]>, the current file as C<$_[2]> and the line number as C<$_[3]>.
82 If and only if the object is actually a block, C<$_[0]> is assured to start by C<'{'>.
86 Otherwise, a warning will be emitted for each indirect construct.
100 } elsif ($arg eq ':fatal') {
101 $hook = sub { die msg(@_) };
105 $hook = sub { warn msg(@_) } unless defined $hook;
108 $^H{+(__PACKAGE__)} = _tag($hook);
115 Magically called at each C<use indirect>. Turns the module off.
120 $^H{+(__PACKAGE__)} = undef;
126 =head2 C<msg $object, $method, $file, $line>
128 Returns the default error message generated by C<indirect> when an invalid construct is reported.
135 join ' ', "Indirect call of method \"$_[1]\" on",
136 ($obj =~ /^\s*\{/ ? "a block" : "object \"$obj\""),
137 "at $_[2] line $_[3].\n";
142 =head2 C<I_THREADSAFE>
144 True iff the module could have been built with thread-safety features enabled.
148 The implementation was tweaked to work around several limitations of vanilla C<perl> pragmas : it's thread safe, and doesn't suffer from a C<perl 5.8.x-5.10.0> bug that causes all pragmas to propagate into C<require>d scopes.
150 C<meth $obj> (no semicolon) at the end of a file won't be seen as an indirect object syntax, although it will as soon as there is another token before the end (as in C<meth $obj;> or C<meth $obj 1>).
152 With 5.8 perls, the pragma does not propagate into C<eval STRING>.
153 This is due to a shortcoming in the way perl handles the hints hash, which is addressed in perl 5.10.
159 L<XSLoader> (standard since perl 5.006).
163 Vincent Pit, C<< <perl at profvince.com> >>, L<http://www.profvince.com>.
165 You can contact me by mail or on C<irc.perl.org> (vincent).
169 Please report any bugs or feature requests to C<bug-indirect at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=indirect>.
170 I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
174 You can find documentation for this module with the perldoc command.
178 Tests code coverage report is available at L<http://www.profvince.com/perl/cover/indirect>.
180 =head1 ACKNOWLEDGEMENTS
182 Bram, for motivation and advices.
184 =head1 COPYRIGHT & LICENSE
186 Copyright 2008-2009 Vincent Pit, all rights reserved.
188 This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.