34 at 34 for v5.34: Modern Perl features for Perl’s birthday
Friday, December 17, 2021, marked the thirty-fourth birthday of the Perl programming language, and coincidentally this year saw the release of version 5.34. There are plenty of Perl developers out there who haven’t kept up with recent (and not-so-recent) improvements to the language and its ecosystem, so I thought I might list a batch. (You may have seen some of these before in May’s post “Perl can do that now!”)
The feature pragma
Perl v5.10 was released in December 2007, and with it came feature, a way of enabling new syntax without breaking backward compatibility. You can enable individual features by name (e.g., use feature qw(say fc); for the say and fc keywords), or by using a feature bundle based on the Perl version that introduced them. For example, the following:
use feature ':5.34';…gives you the equivalent of:
use feature qw(bareword_filehandles bitwise current_sub evalbytes fc indirect multidimensional postderef_qq say state switch unicode_eval unicode_strings);Boy, that’s a mouthful. Feature bundles are good. The corresponding bundle also gets implicitly loaded if you specify a minimum required Perl version, e.g., with use v5.32;. If you…
