NAME
indirect - Lexically warn about using the indirect object syntax.
VERSION
Version 0.16
SYNOPSIS
# In a script
no indirect;
my $x = new Apple 1, 2, 3; # warns
{
use indirect;
my $y = new Pear; # ok
{
no indirect hook => sub { die "You really wanted $_[0]\->$_[1] at $_[2]:$_[3]" };
my $z = new Pineapple 'fresh'; # croaks 'You really wanted Pineapple->new at blurp.pm:13'
}
}
try { ... }; # warns
no indirect ':fatal';
if (defied $foo) { ... } # croaks, note the typo
# From the command-line
perl -M-indirect -e 'my $x = new Banana;' # warns
# Or each time perl is ran
export PERL5OPT="-M-indirect"
perl -e 'my $y = new Coconut;' # warnsDESCRIPTION
When enabled (or disabled as some may prefer to say, since you actually turn it on by calling no indirect), this pragma warns about indirect object syntax constructs that may have slipped into your code. This syntax is now considered harmful, since its parsing has many quirks and its use is error prone (when swoosh isn't defined, swoosh $x actually compiles to $x->swoosh).
It currently does not warn for core functions (print, say, exec or system). This may change in the future, or may be added as optional features that would be enabled by passing options to unimport.
This module is not a source filter.
METHODS
unimport [ hook => $hook | ':fatal' ]
Magically called when no indirect @opts is encountered. Turns the module on. The policy to apply depends on what is first found in @opts :
If it's the string
':fatal', the compilation will croak on the first indirect syntax met.If the key/value pair
hook => $hookcomes first,$hookwill be called for each error with a string representation of the object as$_[0], the method name as$_[1], the current file as$_[2]and the line number as$_[3]. If and only if the object is actually a block,$_[0]is assured to start by'{'.Otherwise, a warning will be emitted for each indirect construct.
import
Magically called at each use indirect. Turns the module off.
FUNCTIONS
msg $object, $method, $file, $line
Returns the default error message generated by indirect when an invalid construct is reported.
CONSTANTS
I_THREADSAFE
True iff the module could have been built with thread-safety features enabled.
DIAGNOSTICS
Indirect call of method "%s" on object "%s" at %s line %d.
The default warning/exception message thrown when an indirect call on an object is found.
Indirect call of method "%s" on a block at %s line %d.
The default warning/exception message thrown when an indirect call on a block is found.
CAVEATS
The implementation was tweaked to work around several limitations of vanilla perl pragmas : it's thread safe, and doesn't suffer from a perl 5.8.x-5.10.0 bug that causes all pragmas to propagate into required scopes.
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 meth $obj; or meth $obj 1).
With 5.8 perls, the pragma does not propagate into eval STRING. This is due to a shortcoming in the way perl handles the hints hash, which is addressed in perl 5.10.
DEPENDENCIES
perl 5.8.
XSLoader (standard since perl 5.006).
AUTHOR
Vincent Pit, <perl at profvince.com>, http://www.profvince.com.
You can contact me by mail or on irc.perl.org (vincent).
BUGS
Please report any bugs or feature requests to bug-indirect at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=indirect. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc indirectTests code coverage report is available at http://www.profvince.com/perl/cover/indirect.
ACKNOWLEDGEMENTS
Bram, for motivation and advices.
Andrew Main and Florian Ragwitz, for testing on real-life code and reporting issues.
COPYRIGHT & LICENSE
Copyright 2008-2009 Vincent Pit, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.