---
name: "Perl::Critic::Policy::ControlStructures::ProhibitDeepNests"
section: "3pm"
platform: "linux"
package: "perl-perl-critic"
version: "1.156-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Perl::Critic::Policy::ControlStructures::ProhibitDeepNests"
---

# Perl::Critic::Policy::ControlStructures::ProhibitDeepNests(3pm)

Don't write deeply nested loops and conditionals.

## NAME

Perl::Critic::Policy::ControlStructures::ProhibitDeepNests - Don't write deeply nested loops and conditionals.

## AFFILIATION

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

## DESCRIPTION

Deeply nested code is often hard to understand and may be a sign that it needs to be refactored.  There are several good books on how to refactor code.  I like Martin Fowler's "Refactoring: Improving The Design of Existing Code".

## CONFIGURATION

The maximum number of nested control structures can be configured via a value for `"max_nests"` in a *.perlcriticrc* file.  Each for-loop, if-else, while, and until block is counted as one nest.  Postfix forms of these constructs are not counted.  The default maximum is 5. Customization in a *.perlcriticrc* file looks like this:

```
    [ControlStructures::ProhibitDeepNests]
    max_nests = 3
```

## AUTHOR

Jeffrey Ryan Thalhammer \<jeff@imaginative-software.com\>

## COPYRIGHT

Copyright (c) 2005-2011 Imaginative Software Systems.  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.