NAME¶

Perl6::Caller - OO "caller()" interface

VERSION¶

Version 0.04

SYNOPSIS¶

 use Perl6::Caller;
 my $sub         = caller->subroutine;
 my $line_number = caller->line;
 my $is_require  = caller(3)->is_require;

EXPORT¶

"caller"¶

 # standard usage
 print "In ",           caller->subroutine,
       " called from ", caller->file,
       " line ",        caller->line;
 # get a caller object
 my $caller = caller;
 my $caller = caller();   # same thing
 # get a caller object for a different stack from
 my $caller = caller(2);  # two stack frames up
 print $caller->package;  # prints the package name
 # enjoy the original flavor
 my @caller = caller;     # original caller behavior
 print $caller[0],        # prints the package name

DESCRIPTION¶

This module is experimental. It's also alpha. Bug reports and patches welcome.

By default, this module exports the "caller" function. This automatically returns a new "caller" object. An optional argument specifies how many stack frames back to skip, just like the "CORE::caller" function. This lets you do things like this:

 print "In ",           caller->subroutine,
       " called from ", caller->file,
       " line ",        caller->line;

If you do not wish the "caller" function imported, specify an empty import list and instantiate a new "Perl6::Caller" object.

 use Perl6::Caller ();
 my $caller = Perl6::Caller->new;
 print $caller->line;

Note: if the results from the module seem strange, please read perldoc -s caller carefully. It has stranger behavior than you might be aware.

METHODS¶

The following methods are available on the "caller" object. They return the same values as documented in perldoc -f caller.

There are no "hints" and "bitmask" methods because those are documented as for internal use only.

• "package"
• "filename"
• "line"
• "subroutine"
• "hasargs"
• "wantarray"
• "evaltext"
• "is_require"

Note that each of these values will report correctly for when the caller object was created. For example, the following will probably print different line numbers:

 print caller->line;
 foo();
 sub foo { 
    print caller->line;
 }

However, the following will print the same line numbers:

 my $caller = Perl6::Caller->new;   # everything is relative to here
 print $caller->line;
 foo($caller);
 sub foo { 
    my $caller = shift;
    print $caller->line;
 }

CAVEATS¶

Most of the time, this package should just work and not interfere with anything else.

• $hints, $bitmask

  'hints' and 'bitmask' are not available. They are documented to be for internal use only and should not be relied upon. Further, the bitmask caused strange test failures, so I opted not to include them.

• Subclassing

  Don't.

• Perl 6

  I'm not entirely comfortable with the namespace. The Perl 6 caller actually does considerably more, but for me to have a hope of working that in, I need proper introspection and I don't have that. Thus, I've settled for simply having a caller object.

• *CORE::GLOBAL::caller

  I didn't implement this, though I was tempted. It turns out to be a bit tricky in spots and I'm very concerned about globally overriding behavior. I might change my mind in the future if there's enough demand.

• Overloading

  In string context, this returns the package name. This is to support the original "caller" behavior.

• List Context

  In list context, we simply default to the original behavior of "CORE::caller". However, this always assumes we've called caller with an argument. Calling "caller" and caller(0) are identical with this module. It's difficult to avoid since the stack frame changes.

AUTHOR¶

Curtis "Ovid" Poe, "<ovid@cpan.org>"

ACKNOWLEDGEMENTS¶

Thanks to "phaylon" for helping me revisit a bad design issue with this.

BUGS¶

Please report any bugs or feature requests to "bug-perl6-caller@rt.cpan.org", or through the web interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Perl6-Caller>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

ACKNOWLEDGEMENTS¶

COPYRIGHT & LICENSE¶

Copyright 2007 Curtis "Ovid" Poe, all rights reserved.

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