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

Langue: en

Autres versions - même langue

Version: 2010-09-08 (fedora - 01/12/10)

Section: 3 (Bibliothèques de fonctions)

Sommaire

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) 2007-2009 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.