Language Update: Perl

by @dankogai

Perl (5|6)?

Perl (5|6)?

Mostly about Perl 5

Then and Now

Then and Now

Encoding

use v5.16;
use utf8;
use encoding 'utf8';

sub ふば {
    ["ふぃず"]->[ $_ % 3 ] 
  . ["ばず"]->[ $_ % 5 ]
  || $_
}
say ふば($_) for 1..30;

Then and Now

use 5.X

my $string = "Hello, world!";
print $str;

use 5.X

use strict;
use warnings;
my $string = "Hello, world!";
print $str;

use 5.X

use v5.16;
my $string = "Hello, world!";
print $str;

use 5.X

use v5.8;
my $string = "Hello, world!";
print $str;

Then and Now

use feature

{
  use feature 'say';
  say ["Fizz"]->[ $_ % 3 ] 
    . ["Buzz"]->[ $_ % 5 ]
      || $_
    for 1..30;
}

use feature

{
  use feature 'say';
  say ["Fizz"]->[ $_ % 3 ] 
    . ["Buzz"]->[ $_ % 5 ]
      || $_
    for 1..30;
}
say "Hello";

__SUB__

use feature qw/say current_sub/;
sub {
  my $n = shift;
  say ["Fizz"]->[ $n % 3 ] 
    . ["Buzz"]->[ $n % 5 ]
    || $n;
  __SUB__->( ++$n ) if $n < 30;
}->(1);

__SUB__

use feature qw/say/;
sub {
  my $n = shift;
  say ["Fizz"]->[ $n % 3 ] 
    . ["Buzz"]->[ $n % 5 ]
    || $n;
  __SUB__->( ++$n ) if $n < 30;
}->(1);

Simply Put

• We have added features…

Simply Put

• We have added features…
• without breaking legacy codes.

Simply Put

• We have added features…
• without breaking legacy codes.
• Your 2002 codes runs unchanged in 2012.

Simply Put

• We have added features…
• without breaking legacy codes.
• Your 2002 codes run unchanged in 2012.
  • Python 2 vs 3?
  • Ruby 1.8 vs 1.9?

Simply Put

• We have added features…
• without breaking legacy codes.
• Your 2002 codes run unchanged in 2012.
  • Python 2 vs 3?
  • Ruby 1.8 vs 1.9?
• Will run in 2022 and years to come.

One more thing

Language Update Decade

• Perl
• PHP
• Python
• Ruby

Language Update Decade

• Perl
• PHP
• Python
• Ruby
• JavaScript?

The most important LL is missing!

The most important LL is missing!

JavaScript the only language

• that runs on both sides
• that runs without installing
• anything else is secondary

JavaScript + Something

JavaScript ∽ Perl

• Both are lightweight languages
  • no compilation
  • objects
  • closures
  • …
• Method names in (String|Array).prototype
• "use strict"

Perl != JavaScript

• Preinstalled in almost all servers
• CPAN
• Shell-friendly
  • cpan(plus|m)?
  • perlbrew
  • one-liners

Use Perl

The following shall remain true for years to come.

• A language for getting your job done.
• Easy thing should be easier, without making hard things harder
• There's more than one way to do it.
  • more than one language to do it.

御礼なう

sub questions {
  answer shift and __SUB__->(@_);
}