Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions(3pm)
                                           User Contributed Perl Documentation


NAME
       Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions
       - Don't use operators like "not", "!~", and "le" within "until" and
       "unless".

AFFILIATION
       This Policy is part of the core Perl::Critic distribution.

DESCRIPTION
           until ($foo ne 'blah') {          #not ok
               ...
           }

           while ($foo eq 'blah') {          #ok
               ...
           }

       A number of people have problems figuring out the meaning of doubly
       negated expressions.  "unless" and "until" are both negative
       constructs, so any negative (e.g. "!~") or reversible operators (e.g.
       "le") included in their conditional expressions are double negations.
       Conway considers the following operators to be difficult to understand
       within "unless" and "until":

         ! not
         !~ ne !=
         <   >   <=  >=  <=>
         lt  gt  le  ge  cmp

CONFIGURATION
       This Policy is not configurable except for the standard options.

SEE ALSO
       Perl::Critic::Policy::ControlStructures::ProhibitUnlessBlocks

AUTHOR
       Elliot Shank "<perl@galumph.com>"

COPYRIGHT
       Copyright (c) 2007-2011 Elliot Shank.

       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.  The full text of this license can
       be found in the LICENSE file included with this module.

perl v5.38.0                      2023-07-26
Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions(3pm)