Provided by: liblexical-failure-perl_0.001001-1_all bug

NAME

       Lexical::Failure::Objects - Special failure objects for Lexical::Failure

VERSION

       This document describes Lexical::Failure::Objects version 0.000001

DESCRIPTION

       This module implements the "failure objects" returned by the optional 'failobj' mechanism of the
       "Lexical::Failure" module.

       When "ON_FAILURE 'failobj'" is in effect, any call to "fail" will return one of these objects, which
       simulates a special out-of-band value that you can either explicitly test for failure or else simply
       ignore and automatically get an exception.

       For example, given the subroutine:

           package Math;
           use Lexical::Failure;

           sub inverse_square {
               my ($n) = @_;

               if ($n == 0) {
                   fail "Can't invert zero";
               }

               return 1/$n**2;
           }

       when 'failobj' is the selected failure signalling strategy:

           use Math (fail => 'failobj')

       then failure can either be tested for explicitly:

           # This block skipped if $n == 0...
           if (my $inv_sq = Math::inverse_square($n) {
               print $inv_sq;
           }

       or else simply ignored, in which case an exception will automatically be thrown:

           print inverse_square($n);    # ...throw exception if $n == 0

INTERFACE

       If it is used as a boolean, a failure object evaluates false (i.e. it acts as if "ON_FAILURE 'undef'" had
       been in effect).

       If it is used as a value in any other way (as a string, as a reference, as a regex, as a filehandle,
       etc., etc.), or if it's ignored and allowed to go out of scope without being evaluated at all, then a
       failure object throws an exception (i.e. it acts as if "ON_FAILURE 'croak'" had been in effect).

   Constructor ("new()")
       The class's constructor expects two named arguments:

           $failure_obj = Lexical::Failure::Objects->new(
                              msg     => $MESSAGE_STR_OR_OBJ,
                              context => [$PACKAGE, $FILE, $LINE, $SUBNAME],
                          );

       You should never normally need to construct failure objects directly; it's better to let
       "Lexical::Failure" craete them automatically via its 'failobj' mechanism.

   Methods
       "Lexical::Failure::Objects" also provides four methods with which you can query the location of the
       failure that they represent. None of these methods takes any arguments.

       "$failobj->subname()"
           Returns  the  name  of  the subroutine in which the failure was signaled.  That is, the equivalent of
           "(caller 0)[3]".

       "$failobj->file()"
           Returns the name of the file containing the subroutine call from which failure  was  signaled.   That
           is, the equivalent of "(caller 0)[1]".

       "$failobj->line()"
           Returns  the  line  number  of  the  subroutine  call  from which failure was signaled.  That is, the
           equivalent of "(caller 0)[2]".

       "$failobj->context()"
           Returns a string summarizing the information provided by the previous three methods, in the form:

               "call to <subname> at <file> line <line>"

DIAGNOSTICS

       None of their own.

       If they throw an exception (when misused or  ignored),  it  will  be  the  exception  that  "fail"  would
       otherwise have thrown.

CONFIGURATION AND ENVIRONMENT

       Lexical::Failure::Objects requires no configuration files or environment variables.

DEPENDENCIES

       Requires the Hash::Util::FieldHash module.

INCOMPATIBILITIES

       None reported.

BUGS AND LIMITATIONS

       No bugs have been reported.

       Please  report  any  bugs  or  feature  requests to "bug-lexical-failure@rt.cpan.org", or through the web
       interface at <http://rt.cpan.org>.

AUTHOR

       Damian Conway  "<DCONWAY@cpan.org>"

LICENCE AND COPYRIGHT

       Copyright (c) 2013, Damian Conway "<DCONWAY@cpan.org>". All rights reserved.

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

DISCLAIMER OF WARRANTY

       BECAUSE  THIS  SOFTWARE  IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT
       PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS  AND/OR  OTHER
       PARTIES  PROVIDE  THE  SOFTWARE  "AS  IS"  WITHOUT  WARRANTY  OF  ANY  KIND, EITHER EXPRESSED OR IMPLIED,
       INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND  FITNESS  FOR  A  PARTICULAR
       PURPOSE.  THE  ENTIRE  RISK  AS  TO  THE  QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE
       SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

       IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER,  OR  ANY
       OTHER  PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
       TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING  OUT  OF
       THE  USE  OR  INABILITY  TO  USE  THE  SOFTWARE  (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
       RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE  TO  OPERATE
       WITH  ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
       DAMAGES.

perl v5.36.0                                       2023-08-01                     Lexical::Failure::Objects(3pm)