Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa3pm
Write "eval { $foo->isa($pkg) }" instead of "universal::isa($foo, $pkg)".
Affiliation
This Policy is part of the core Perl::Critic distribution.
Overview
print UNIVERSAL::isa($obj, 'Foo::Bar') ? 'yes' : 'no'; #not okprint eval { $obj->isa('Foo::Bar') } ? 'yes' : 'no'; #ok
As of Perl 5.9.3, the use of "UNIVERSAL::isa" as a function has been deprecated and the method form is preferred instead. Formerly, the functional form was recommended because it gave valid results even when the object was "undef" or an unblessed scalar. However, the functional form makes it impossible for packages to override isa(), a technique which is crucial for implementing mock objects and some facades.
Another alternative to UNIVERSAL::isa is the "_INSTANCE" method of Param::Util, which is faster.
See the CPAN module UNIVERSAL::isa for an incendiary discussion of this topic.
Configuration
This Policy is not configurable except for the standard options.
Releases
10 releases since Debian 5.0 (Lenny); the text changed 9 times.