Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions.3pm

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Version: 2009-02-26 (fedora - 04/07/09)

Section: 3 (Bibliothèques de fonctions)

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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 (c) 2007-2008 Elliot Shank. All rights reserved.

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.