What is new in Perl 5.10? Paul Fenwick Audrey Tang Leon Brocard

Paul Fenwick

Audrey Tang

Leon Brocard

slidehist Monday: I'm presenting? Tuesday: download Paul's slides Wednesday: tweak design Thursday: play with fonts Friday: argh slides on a plane Saturday: release!

Monday: I'm presenting?

Tuesday: download Paul's slides

Wednesday: tweak design

Thursday: play with fonts

Friday: argh slides on a plane

Saturday: release!

perlhist 1987: 1.0 1988: 2.0 1989: 3.0... 1991: 4.0... 1994: 5.0

1987: 1.0

1988: 2.0

1989: 3.0...

1991: 4.0...

1994: 5.0

perlhist 5.0 1994: 5.0 1995: 5.1 1996: 5.2, 5.3 1997: 5.4 1998: 5.5... 2000: 5.6... 2002: 5.8

1994: 5.0

1995: 5.1

1996: 5.2, 5.3

1997: 5.4

1998: 5.5...

2000: 5.6...

2002: 5.8

5.8 perlhist 2002: 5.8.0 2003: 5.8.1, 5.8.2 2o04: 5.8.3, 5.8.4, 5.8.5, 5.8.6 2005: 5.8.7 2006: 5.8.8

2002: 5.8.0

2003: 5.8.1, 5.8.2

2o04: 5.8.3, 5.8.4, 5.8.5, 5.8.6

2005: 5.8.7

2006: 5.8.8

2007 Stable: 5.8.9 New: 5.10 New new: 6.0.0

Stable: 5.8.9

New: 5.10

New new: 6.0.0

New features Perl 5.10 has new features Sorry Sebastian

Perl 5.10 has new features

Sorry Sebastian

New? new lexically-scoped feature pragma: use feature qw(say switch); use feature qw(:5.10); use 5.10;

new lexically-scoped feature pragma:

use feature qw(say switch);

use feature qw(:5.10);

use 5.10;

Optimise programmer time Most advanced programming language ever! Perl: print “hello
” Perl 6: say “hello” Perl 5.10: say “hello”

Most advanced programming language ever!

Perl: print “hello
”

Perl 6: say “hello”

Perl 5.10: say “hello”

Save typing My poor fingers! Also none of this nasty quoting business This might seem like it's trivial...

My poor fingers!

Also none of this nasty quoting business

This might seem like it's trivial...

Or $c = $a | | $b is handy confused by empty string, undef or zero

$c = $a | | $b is handy

confused by empty string, undef or zero

Defined or $c = $a // $b is handier same as $c = defined($a) ? $a : $b

$c = $a // $b is handier

same as $c = defined($a) ? $a : $b

dor and err There's also low-precedence // use feature qw(dor err); fileno($x) dor die 'That's not a filehandle'; fileno($x) err die 'That's not a filehandle';

There's also low-precedence //

use feature qw(dor err);

fileno($x) dor die 'That's not a filehandle';

fileno($x) err die 'That's not a filehandle';

State variables The old way of having a persistent variable: { my $i = 0; sub incrementor { return $i++; } }

The old way of having a persistent variable:

{ my $i = 0; sub incrementor { return $i++; } }

State variables use feature 'state'; sub incrementor { state $i = 0; return $i++; }

use feature 'state'; sub incrementor { state $i = 0; return $i++; }

Local caches State variables can live deep inside subroutines... for my $x (...) { for my $y (...) { state %seen; next if $seen{$x}{$y}++; } }

State variables can live deep inside subroutines...

for my $x (...) { for my $y (...) { state %seen; next if $seen{$x}{$y}++; } }

Switch Perl 5.10 introduces a native switch statement. Similar to Perl 6's switch, and Switch.pm (source filter) Built into the Perl interpreter

Perl 5.10 introduces a native switch statement.

Similar to Perl 6's switch, and Switch.pm (source filter)

Built into the Perl interpreter

Guessing Game use feature qw(switch say); my @guessed; my $num = int(rand 100)+1; while (my $guess = <STDIN>) { chomp $guess; given($guess) { when (/D/) { say &quot;Give me an integer&quot; } when (@guessed) { say &quot;You've tried that&quot; } when ($num) { say &quot;Just right!&quot;; last } when ($_ < $num) { say &quot;Too low&quot;; continue } when ($_ > $num) { say &quot;Too high&quot;; continue } push(@guessed,$_); } }

use feature qw(switch say); my @guessed; my $num = int(rand 100)+1; while (my $guess = <STDIN>) { chomp $guess; given($guess) { when (/D/) { say &quot;Give me an integer&quot; } when (@guessed) { say &quot;You've tried that&quot; } when ($num) { say &quot;Just right!&quot;; last } when ($_ < $num) { say &quot;Too low&quot;; continue } when ($_ > $num) { say &quot;Too high&quot;; continue } push(@guessed,$_); } }

foreach / when use feature 'switch'; foreach (@cool_things) { when (/pirate/) { $pirate++ } when (/ninja/) { $ninja++ } when (/robot/) { $robot++ } say &quot;$_ doesn't look cool...&quot;; } when automatically calls next at the end of its block

use feature 'switch'; foreach (@cool_things) { when (/pirate/) { $pirate++ } when (/ninja/) { $ninja++ } when (/robot/) { $robot++ } say &quot;$_ doesn't look cool...&quot;; }

when automatically calls next at the end of its block

Smart-match use feature '~~'; if ($x ~~ @array) { say &quot;$x exists&quot; } if ($x ~~ /ninja/) { say &quot;Ninja in string&quot;} if (@x ~~ /ninja/) { say &quot;Ninja in array&quot; } if ($key ~~ %hash) { say &quot;$key exists&quot; } if ($subref ~~ $arg) { say 'sub($arg) true' }

use feature '~~'; if ($x ~~ @array) { say &quot;$x exists&quot; } if ($x ~~ /ninja/) { say &quot;Ninja in string&quot;} if (@x ~~ /ninja/) { say &quot;Ninja in array&quot; } if ($key ~~ %hash) { say &quot;$key exists&quot; } if ($subref ~~ $arg) { say 'sub($arg) true' }

Smart-match use feature '~~'; if (@array ~~ $x) { say &quot;$x exists&quot; } if (/ninja/ ~~ $x) { say &quot;Ninja in string&quot;} if (/ninja/ ~~ @x) { say &quot;Ninja in array&quot; } if (%hash ~~ $key) { say &quot;$key exists&quot; } if ($arg ~~ $subref) { say 'sub($arg) true' } ~~ can be overloaded

use feature '~~'; if (@array ~~ $x) { say &quot;$x exists&quot; } if (/ninja/ ~~ $x) { say &quot;Ninja in string&quot;} if (/ninja/ ~~ @x) { say &quot;Ninja in array&quot; } if (%hash ~~ $key) { say &quot;$key exists&quot; } if ($arg ~~ $subref) { say 'sub($arg) true' }

~~ can be overloaded

UNIVERSAL::DOES Traditionally isa would be used to determine the capabilities of a class: provides a way to show compatibility, without inheritance $obj‐>isa('Logger'); $obj‐>DOES('Logger');

Traditionally isa would be used to determine the capabilities of a class:

provides a way to show compatibility, without inheritance

$obj‐>isa('Logger');

$obj‐>DOES('Logger');

Helicopter package Helicopter; sub DOES { my ($this, $interface) = @_; return 1 if ($interface eq &quot;Airplane&quot;); return $this->SUPER::does($interface); }

package Helicopter; sub DOES { my ($this, $interface) = @_; return 1 if ($interface eq &quot;Airplane&quot;); return $this->SUPER::does($interface); }

Constant (un-)folding Perl 'folds' constants at compile time 9+5 gets converted to 14 In Perl 5.10, exceptional constants are unfolded They'll still throw run-time exceptions if you try to execute them

Perl 'folds' constants at compile time

9+5 gets converted to 14

In Perl 5.10, exceptional constants are unfolded

They'll still throw run-time exceptions if you try to execute them

Hash::Util::FieldHash 5.10 comes with support for Field Hashes, which: Can use references as hash keys Reference-keys migrate correctly across threads Entries to stale references are automatically deleted (Inside-Out objects work nicely)

5.10 comes with support for Field Hashes, which:

Can use references as hash keys

Reference-keys migrate correctly across threads

Entries to stale references are automatically deleted

(Inside-Out objects work nicely)

Assertions Perl 5.10 implements real assertions Normally compiled away Can be enabled on a per-module basis # This is normally compiled away sub assert_sanity :assertion {...} # Enable assertions for MyModule perl -A=MyModule prog.pl

Perl 5.10 implements real assertions

Normally compiled away

Can be enabled on a per-module basis

# This is normally compiled away sub assert_sanity :assertion {...} # Enable assertions for MyModule perl -A=MyModule prog.pl

User-defined lexical pragmata We've used lexical pragmata for years: { use strict; ... } In Perl 5.10 you can write your own! %^H allows &quot;hints&quot; to be attached to the optree use feature is implemented this way

We've used lexical pragmata for years: { use strict; ... }

In Perl 5.10 you can write your own!

%^H allows &quot;hints&quot; to be attached to the optree

use feature is implemented this way

More modules encoding::warnings Math::BigInt::FastCalc Time::Piece Win32API::File CPANPLUS

encoding::warnings

Math::BigInt::FastCalc

Time::Piece

Win32API::File

CPANPLUS

CPANPLUS Hi Jos! It's about time, isn't it? Means we have many other modules in the core...

Hi Jos!

It's about time, isn't it?

Means we have many other modules in the core...

Regex engine perlreguts No longer recursive Single char char-classes treated as literals Trie optimisation of literal string alternations /foam|foal|foad/ => /foa[mld]/ Aho-Corasick start-point optimisation Regex engine Pluggable: use re::engine::PCRE; Named capture buffers /$(?<price>d+)/ ... $+{price} More

perlreguts

No longer recursive

Single char char-classes treated as literals

Trie optimisation of literal string alternations /foam|foal|foad/ => /foa[mld]/

Aho-Corasick start-point optimisation

Regex engine

Pluggable: use re::engine::PCRE;

Named capture buffers

/$(?<price>d+)/ ... $+{price}

More

Other goodies Misc Attribute Decoration $AUTOLOAD can be tainted Source filters in @INC encodings::warnings is lexical Better threads Faster UTF-8

Misc Attribute Decoration

$AUTOLOAD can be tainted

Source filters in @INC

encodings::warnings is lexical

Better threads

Faster UTF-8

More other goodies Faster stat() on Windows Relocatable installs Overloading for re-blessed objects Better Windows support Smaller memory footprint (slightly faster) More documentation

Faster stat() on Windows

Relocatable installs

Overloading for re-blessed objects

Better Windows support

Smaller memory footprint (slightly faster)

More documentation

More details? http://search.cpan.org/dist/perl/pod/perl594delta.pod

http://search.cpan.org/dist/perl/pod/perl594delta.pod

Questions?

When will it be out? Stable: 5.8.9 “by April 1st” New: 5.10 “after lunch, before Christmas” New new: 6.0.0 “after lunch, before Christmas”

Stable: 5.8.9 “by April 1st”

New: 5.10 “after lunch, before Christmas”

New new: 6.0.0 “after lunch, before Christmas”

Any other questions?

License These slides are Copyright 2006 Paul Fenwick, Audrey Tang, Leon Brocard The text may be distributed under your choice of any of the following: The license terms of Perl itself GNU Free Documentation License Creative Commons Attribution ShareAlike

These slides are Copyright 2006 Paul Fenwick, Audrey Tang, Leon Brocard

The text may be distributed under your choice of any of the following:

The license terms of Perl itself

GNU Free Documentation License

Creative Commons Attribution ShareAlike