NAME¶

Perl::Critic::Policy::BuiltinFunctions::ProhibitComplexMappings - Map blocks should have a single statement.

AFFILIATION¶

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

DESCRIPTION¶

The map function can be confusing to novices in the best of circumstances. Mappings with multiple statements are even worse. They're also a maintainer's nightmare because any added complexity decreases readability precipitously. Why? Because map is traditionally a one-liner converting one array to another. Trying to cram lots of functionality into a one-liner is a bad idea in general.

The best solutions to a complex mapping are: 1) write a subroutine that performs the manipulation and call that from map; 2) rewrite the map as a for loop.

CAVEATS¶

This policy currently misses some compound statements inside of the map. For example, the following code incorrectly does not trigger a violation:

    map { do { foo(); bar() } } @list

CONFIGURATION¶

By default this policy flags any mappings with more than one statement. While we do not recommend it, you can increase this limit as follows in a .perlcriticrc file:

    [BuiltinFunctions::ProhibitComplexMappings]
    max_statements = 2

AUTHOR¶

Chris Dolan <cdolan@cpan.org>

CREDITS¶

Initial development of this policy was supported by a grant from the Perl Foundation.

COPYRIGHT¶

Copyright (c) 2007-2011 Chris Dolan.

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