/ 
Exception-Warning-0.01
River stage one • 2 direct dependents • 6 total dependents
/ Exception::Warning

NAME

Exception::Warning - Convert simple warn into real exception object

SYNOPSIS

# Convert warn into exception and throw it immediately
use Exception::Warning '%SIG' => 'die';
eval { warn "Boom!"; };
print ref $@;        # "Exception::Warning"
print $@->warning;   # "Boom!"

# Convert warn into exception without die
use Exception::Warning '%SIG' => 'warn', verbosity => 4;
warn "Boom!";   # dumps full stack trace

# Can be used in local scope only
{
    local $SIG{__WARN__} = \&Exception::Warning::__WARN__;
    warn "Boom!";   # warn via exception
}
warn "Boom!";       # standard warn

# Run Perl with verbose warnings
perl -MException::Warning=%SIG,warn,verbosity=>3 script.pl

# Run Perl which dies on first warning
perl -MException::Warning=%SIG,die,verbosity=>3 script.pl

# Run Perl which ignores any warnings
perl -MException::Warning=%SIG,warn,verbosity=>0 script.pl

DESCRIPTION

This class extends standard Exception::Base and converts warning into real exception object. The warning message is stored in warning attribute.

BASE CLASSES

IMPORTS

use Exception::Died '%SIG' [ => 'warn' ];

Changes $SIG{__WARN__} hook to Exception::Died::__WARN__ function.

use Exception::Died '%SIG' => 'die';

Changes $SIG{__WARN__} hook to Exception::Died::__DIE__ function.

ATTRIBUTES

This class provides new attributes. See Exception::Base for other descriptions.

message (ro)

Contains the message which is set by $SIG{__WARN__}.

METHODS

stringify([$verbosity[, $message]])

Returns the string representation of exception object. It is called automatically if the exception object is used in scalar context. The method can be used explicity and then the verbosity level can be used.

The format of output is "message: warning".

PRIVATE FUNCTIONS

__WARN__

This is a hook function for $SIG{__WARN__}. It converts the warning into exception object which is immediately stringify to scalar and printed with warn core function. This hook can be enabled with pragma:

use Exception::Died '%SIG' => 'warn';

or manually, i.e. for local scope:

local $SIG{__WARN__} = \&Exception::Died::__WARN__;
__DIE__

This is a hook function for $SIG{__DIE__}. It converts the warning into exception object which is immediately thrown. This hook can be enabled with pragma:

use Exception::Died '%SIG' => 'die';

or manually, i.e. for local scope:

local $SIG{__WARN__} = \&Exception::Died::__DIE__;

PERFORMANCE

The Exception::Warning module can change $SIG{__WARN__} hook. It costs a speed for simple warn operation. It was tested against unhooked warn.

-------------------------------------------------------
| Module                              |         run/s |
-------------------------------------------------------
| undef $SIG{__WARN__}                |      276243/s |
-------------------------------------------------------
| $SIG{__WARN__} = sub { }            |      188215/s |
-------------------------------------------------------
| Exception::Warning '%SIG'           |        1997/s |
-------------------------------------------------------
| Exception::Warning '%SIG', verb.=>0 |      152348/s |
-------------------------------------------------------

It means that Exception::Warning is significally slower than simple warn. It is usually used only for debugging purposes, so it shouldn't be an important problem.

SEE ALSO

Exception::Base.

BUGS

If you find the bug, please report it.

AUTHOR

Piotr Roszatycki <dexter@debian.org>

LICENSE

Copyright (C) 2008 by Piotr Roszatycki <dexter@debian.org>.

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

See http://www.perl.com/perl/misc/Artistic.html