Bag of tricks

My Perl
Bag of Tricks

brian d foy
The Perl Review
YAPC::Brasil 2011

http://slidesha.re/s06nuv

• Eliminate special cases
• Remove distractions
• Know less
• Let Perl do the work
• Scale gracefully

% perl -e "print qq(Alo Mundon)"

% perl -le "print q(Alo Mundo)"

my $string = some_sub();

open my $fh, '<', $string;

while(<$fh>){
chomp;
...;
}

use 5.014;

my $new = $old =~ s/.../.../r;

foo( $old =~ s/.../.../r );

print "%s %sn",
$old,
$old =~ s/.../.../r
;

foreach my $file ( @files ) {
open my($fh), '>', $file or do {
warn "... $!n";
next FILE;
};
...
}

my $data = do {
local $/; <DATA>
};
...;

__END__
<?xml version="1.0"?>
<root>
...
</root>

my $data = do { local $/; <DATA> };

s|.*(?=<elem>)||; s|(?<=</elem>).*||;

my $name =
m|<elem>(.*?)</elem>|;

__END__
<?xml version="1.0"?>
<root>
...<elem>Buster</elem>
</root>

$g =
q("Mimi","Bean,Buster","Roscoe");

my @gatos = split /(?<="),(?=")/, $g;

$g =
q("Roscoe "","" Cat","Bean, Buster");

my @gatos =
split
/(?<!"")(?<="),(?=")(?!"")/, $g;

if( ref $r eq 'ARRAY' )

if( ref $r eq ref [] )

if( ref $r eq ref {} )

if( ref $r eq ref sub {} )

if( ref $r eq ref qr// )

join "n", @entries, '';

join "nt", "t", @entries;

BEGIN {
use Foo;
package Foo;
no warnings qw(redefine);
sub foo { ... }
}

# Git::CPAN::Patch

% git cpan-init http://...
... hack hack hack ...
% git commit
% git cpan-sendpatch

my $file = MPEG::Info->new( ... );

print
join $/,
map {
$file->$_()
} qw(acodec
acodecraw
achans
...
);

package Modulino {
run(@ARGV) unless caller;

sub run {
my @args = @_;
...;
}

}

if( /p{IsUppercaseRoman}/ ) {
...}

# ⅠⅤⅩⅬⅭⅮⅯↁↂↇↈ
sub IsUppercaseRoman {
return <<"CODE_NUMBERS";
2160
2164
2169
216C 216F
2181 2182
2187 2188
CODE_NUMBERS
}

printf
'%1$#b %1$#o %1$d %1$#xn",
137;

# 0b10001001 0211 137 0x89

gato( nome => 'Buster' );

sub gato {
my %defaults = (...);
my %config = (%defaults, @_ );
...;
}

BEGIN {
my $fixed_time = 1234567890;
no warnings qw(redefine);

*CORE::GLOBAL::time =
sub { $fixed_time };

sub set_time {
$fixed_time = $_[0]
}
}

ok( time > $fixed_time );

sub my_grep (&@) {
my( $sub ) = shift;

foreach my $arg ( @_ ) {
local $_ = $arg;
push @output, $arg
if $sub->()
}
}

my $ucfirst_and_trim =
composer(
&trim_front,
&trim_back,
&my_ucfirst
);

$s = $ucfirst_and_trim->($s);

sub composer {
my (@sub_refs) = @_;
sub {
my $string = shift;
foreach my $sub_ref (@sub_refs) {
$string = $sub_ref->($string);
}
return $string;
};
}

my @tests = (
# ARG EXPECTED LABEL
[ [1,2,3], 6, 'Sum is 6' ],
[ [-1,0,9], 8, 'Sum is 8' ],
...
);

foreach my $test ( @tests ) {
is(
target_sub( $test->[ARG] ),
$test->[EXPECTED],
$test->[LABEL]
);
}

package Local::Null::Logger {
sub new { bless my $x, $_[0] }
sub AUTOLOAD { shift; print @_, $/ }
sub DESTROY { 1 }
}

sub _init_logger {
my $log4perl_loaded =
eval "require Log::Log4perl; 1";

unless( $log4perl_loaded ){
return Local::Null::Logger->new;
}
...;
}

$object->foo->bar->baz->quux;

package Class {
sub bar {
return Null->new if $error;
}
}

package Null {
my $null = bless {}, __PACKAGE__;
sub new { $null }
sub AUTOLOAD { return $_[0] }
sub DESTROY { 1 }
}

Obrigado

http://slidesha.re/s06nuv

http://commons.wikimedia.org/wiki/File:Pelé_jump_1958.jpg

http://commons.wikimedia.org/wiki/File:Brazilian_National_Congress.jpg

Bag of tricks

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Bag of tricks