Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep(3pm)

Affiliation

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

Overview

"map" and "grep" are intended to be pure functions, not mutators. If you want to iterate with side-effects, then you should use a proper "for" or "foreach" loop.

    grep{ print frobulate($_) } @list;           #not ok
    print map{ frobulate($_) } @list;            #ok
    grep{ $_ = lc $_ } @list;                    #not ok
    for( @list ){ $_ = lc $_  };                 #ok
    map{ push @frobbed, frobulate($_) } @list;   #not ok
    @frobbed = map { frobulate($_) } @list;      #ok

Configuration

This Policy is not configurable except for the standard options.

Releases

10 releases since Debian 5.0 (Lenny); the text changed 9 times.

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6.0
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Arch