Perl 5.20 optimizes return at the end of a subroutine

Want to save 10 nanoseconds? Perl v5.20 optimizes a return at the end of a subroutine to use two fewer ops in the optimized version. During compilation, a subroutine like this one: » Read more…

Perl 5.20 uses its own random number generator

Prior to v5.20, perl used whatever random number generator the system provided. This meant that the same program could have statistically different results based on the quality of that function. The rand() for Windows had a max of 32,768 (15 bits), while POSIX has drand48 (48 bits). This sort of numerical un-portability has always been a problem with perl since it’s relied on the underlying libc for so much. » Read more…

Perl 5.20 new features

Perl 5.20 is out and there are some nice syntax changes that make life easier for Perlers, along with some improvements that don’t require any work from you. Some of the features are experimental, so be careful that you don’t create problems by overusing them until they settle down.

You can download the Perl source from CPAN. For Windows, Strawberry Perl 5.20 is available now. The full details are in the perldelta » Read more…

Declare packages outside of their block

Perl v5.14 gets a step closer to a saner way to declare classes with its new package NAME BLOCK syntax that lets you easily group everything that goes in a package. » Read more…

Experimental features now warn (reaching back to v5.10)

Perl 5.18 provides a new way to introduce experimental features in a program, augmenting the feature pragma that v5.10 added. This change marks certain broken v5.10 features as experimental with an eye toward possible removal from the language.

Smart matching in v5.10 led to several broken and conflated features. The given used a lexical version of $_, which broke many other common uses of that variable inside the given, which I explain in Use for() instead of given() and you can see in given/when and lexical $_ …. » Read more…

Perl 5.18 new features

Perl v5.18 is out and there are some major changes that you should know about before you upgrade. Most notably, some features from v5.10 are now marked experimental. If you use those features, you get warnings.

You can download the Perl source from CPAN. For Windows, Strawberry Perl 5.18 is available now. » Read more…

The vertical tab is part of \s in Perl 5.18

Up to v5.18, the vertical tab wasn’t part of the \s character class shortcut for ASCII whitespace. No one really knows why. It was curious trivia that I pointed out in Know your character classes under different semantics. Whitespace in ASCII, POSIX, and Unicode represented different sets. Perl whitespace was different from POSIX whitespace by only the exclusion of the vertical tab. Now that little oversight is fixed. » Read more…

Perl v5.12 adds the package NAME VERSION syntax

Perl v5.12 modifies the package statement to take a version as well as a name. This allows you to implicitly declare the $VERSION variable: » Read more…

The Perl 5.12 yada yada operator

Perl v5.12 adds a placeholder operator, ..., called the yada yada operator, after an episode of Seinfeld where the interesting parts of the story are replaced with “yada yada yada”. » Read more…

Effective Perler discounts during OSCON

I’ll be at OSCON on Tuesday, July 17, but you don’t have to find me to get up to 37% off Effective Perl Programming. That’s a slightly lower price than Amazon. To get that discount, you have to buy the book at Pearson’s booth in the exhibition hall. You’ll need to track me down on Tuesday afternoon or evening if you want me to sign your book.

If you can’t make it to OSCON, you can still get 35% off the cover price by ordering directly from the InformIT discount link or using the OSCON2012 discount code when you check out. Instead of navigating their site, you can go directly to our book.

If you’re not sure you want the book, you can look at a free sample chapter, which is also 35% off during OSCON.