Perl::Critic::Policy::Subroutines::ProtectPrivateSubs3pm

Affiliation

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

Overview

By convention Perl authors (like authors in many other languages) indicate private methods and variables by inserting a leading underscore before the identifier. This policy catches attempts to access private variables from outside the package itself.

The subroutines in the POSIX package which begin with an underscore (e.g. "POSIX::_POSIX_ARG_MAX") are not flagged as errors by this policy.

Configuration

You can define what a private subroutine name looks like by specifying a regular expression for the "private_name_regex" option in your .perlcriticrc:

    [Subroutines::ProtectPrivateSubs]
    private_name_regex = _(?!_)\w+

The above example is a way of saying that subroutines that start with a double underscore are not considered to be private. (Perl::Critic, in its implementation, uses leading double underscores to indicate a distribution-private subroutine-- one that is allowed to be invoked by other Perl::Critic modules, but not by anything outside of Perl::Critic.)

You can configure additional subroutines to accept by specifying them in a space-delimited list to the "allow" option:

    [Subroutines::ProtectPrivateSubs]
    allow = FOO::_bar FOO::_baz

These are added to the default list of exemptions from this policy. Allowing a subroutine also allows the corresponding method call. So "FOO::_bar" in the above example allows both FOO::_bar() and "FOO->_bar()".