---
name: "Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks"
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::ProhibitUntilBlocks"
---

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

Write "while(! $condition)" instead of "until($condition)".

## NAME

Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks - Write "while(! $condition)" instead of "until($condition)".

## AFFILIATION

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

## DESCRIPTION

Conway discourages using `"until"` because it leads to double-negatives that are hard to understand.  Instead, reverse the logic and use `"while"`.

```
    until($condition)     { do_something() } #not ok
    until(! $no_flag)     { do_something() } #really bad
    while( ! $condition)  { do_something() } #ok
```

This Policy only covers the block-form of `"until"`.  For the postfix variety, see `"ProhibitPostfixControls"`.

## CONFIGURATION

This Policy is not configurable except for the standard options.

## SEE ALSO

Perl::Critic::Policy::ControlStructures::ProhibitPostfixControls

## 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.