Perl 6
Best Of Perl 6 Tablet: Revision 29
"Intro"[Perl 6 Intro Tablet] - _Chapter:_ "0:History"[Perl 6 History Tablet] "1:Design"[Perl 6 Language Design Tablet] "2:Basics"[Perl 6 Basics Tablet] "3:Var"[Perl 6 Variable Tablet] "4:Op"[Perl 6 Operator Tablet] "5:IO"[Perl 6 IO Tablet] "6:{}"[Perl 6 Block Tablet] "7:Sub"[Perl 6 Subroutine Tablet] "8:OOP"[Perl 6 OOP Tablet] "9:Rx"[Perl 6 Regex Tablet] "10:Meta"[Perl 6 Meta Tablet]
"Overview"[Perl 6 Tablets] - _Appendices:_ "A:Index"[Perl 6 Index Tablet] "B:Tables"[Perl 6 Lookup Tablet] "C:Cook"[Perl 6 Cookbook Tablet] "D:Delta"[Perl 6 Delta Tablet] *"E:Best of"[Best Of Perl 6 Tablet]* "F:Links"[Perl 6 Links Tablet] "G:Glossary"[Perl 6 Glossary Tablet]
----
{toc: }
This is a small tour, showing the best features and improvements of Perl 6 in short examples, compared to similar working Perl 5 examples.
^^^ Command Line
"Making output"{link: [Perl 6 IO Tablet]Command Line} will become simpler and easier for newbies.
.pre
Perl 5 Perl 6
print "bananas are good\n"; say "bananas are good";
print "and I said: $quotes{\"me\"}\n"; say "and I said: %quotes{"me"}.";
print "and I said: $quotes{\"me\"}\n"; say "and I said: %quotes<me>.";
print "What is ... "; $result = prompt "What is ... ";
chomp($result = <>);
.pre
^^^ File IO
File::Slurp is in the Perl 6 core language and "file reading"{link: [Perl 6 IO Tablet]File} is simpler then ever (and autochomp included).
.pre
Perl 5 Perl 6
$content = do { local $/; $content = slurp "poetry.txt";
open my $FH, "poetry.txt"; <$FH>
};
chomp(@content = do { @content = lines "poetry.txt";
open my $FH, "poetry.txt"; <$FH>
});
.pre
^^^ Automatic multithreading
Applying operations to junctions and arrays is now syntactically compact and readable. Perl 6 will create threads where appropriate to use multiple processors, cores or hyperthreading for high level language SIMD concurrent processing.
.pre
Perl 5 Perl 6
my $sum; my $sum = [+] @numbers;
$sum += $_ for @numbers;
for (0 .. $#factor1) { @product = @factor1 >>*<< @factor2;
$product[$] = $factor1[$] * $factor2[$_];
}
.pre
The Perl 5 code is a simplification, of course Perl6 "does the right thing" when the arrays have different lengths.
^^^ Comparison
Here are junctions, then chained comparison operators.
.pre
Perl 5 Perl 6
if ($a == 3 or $a == 4 or $a == 7) {...} if $a = 3 | 4 | 7 {...}
if (4 < $a and $a < 12) {...} if 4 < $a < 12 {...}
if (4 < $a and $a <= 12) {...} if $a ~~ 4^..12 {...}
$a = defined $b ? $b : $c; $a = $b // $c;
.pre
The defined-OR operator eases lot of cases where Perl 5 newbies could fall into traps.
^^^ Case construct
.pre
Perl 5 Perl 6
given $a {
if ($a == 2 or $a == 5) {...} }} when 2 | 5 {...}
elsif ($a == 6 or $a == 7 or $a == 8 or $a == 9) {} when 6 .. 9 {...}
elsif ($a =~ /g/) {...} when 'g' {...}
else {...} default {...}
}
.pre
"That new construct"{link: [Perl 6 Block Tablet]given} (backported to 5.10) is clear to read, very versatile and when used in combination with junctions, becomes even clearer.
^^^ Powerful for loops
"List iteration via for"{link: [Perl 6 Block Tablet]for} is now much more versatile.
.pre
Perl 5 Perl 6
for my $i (0..15) {...} for ^16 -> $i {...}
for (my $i=15; $i>1; $i-2) {...} for 15,*-2...1 -> $i {...}
for my $key (keys %hash) { for %hash.kv -> $key, $value {
print "$key => $hash{$key}\n"; ... say "$key => $value"; ...
for my $i (0..$#a) { for zip(@a; @b; @c) -> $a, $b, $c {...}
my $a = @a[$i];
my $b = @b[$i];
my $c = @c[$i]; ...
.pre
^^^ Named parameters in subroutines
.pre
Perl 5 Perl 6
sub routine { sub routine ($a, $b, *@rest) {...}
my $a = shift;
my $b = shift;
my @rest = @_;
}
.pre
^^^ Objects with auto generated new and getters and setters
Simple Object creation is now as easy as it gets.
.pre
Perl 5 Perl 6
package Heart::Gold; class Heart::Gold {
has $.speed;
sub new { method stop { $.speed = 0 }
bless {speed => 0 }, shift; }
}
my Heart::Gold $hg1 .= new;
sub speed { $hg1.speed = 100;
my $self = shift; my $hg2 = $hg1.clone;
my $speed = shift;
if (defined $speed) { $self->{speed} = $speed }
else { $self->{speed} }
}
sub stop {
my $self = shift;
$self->{speed} = 0;
}
.pre
The new, getter, setter and clone methods are auto generated. Methods now are called "method".
----
"Intro"[Perl 6 Intro Tablet] - _Chapter:_ "0:History"[Perl 6 History Tablet] "1:Design"[Perl 6 Language Design Tablet] "2:Basics"[Perl 6 Basics Tablet] "3:Var"[Perl 6 Variable Tablet] "4:Op"[Perl 6 Operator Tablet] "5:IO"[Perl 6 IO Tablet] "6:{}"[Perl 6 Block Tablet] "7:Sub"[Perl 6 Subroutine Tablet] "8:OOP"[Perl 6 OOP Tablet] "9:Rx"[Perl 6 Regex Tablet] "10:Meta"[Perl 6 Meta Tablet]
"Overview"[Perl 6 Tablets] - _Appendices:_ "A:Index"[Perl 6 Index Tablet] "B:Tables"[Perl 6 Lookup Tablet] "C:Cook"[Perl 6 Cookbook Tablet] "D:Delta"[Perl 6 Delta Tablet] *"E:Best of"[Best Of Perl 6 Tablet]* "F:Links"[Perl 6 Links Tablet] "G:Glossary"[Perl 6 Glossary Tablet]
----
"Overview"[Perl 6 Tablets] - _Appendices:_ "A:Index"[Perl 6 Index Tablet] "B:Tables"[Perl 6 Lookup Tablet] "C:Cook"[Perl 6 Cookbook Tablet] "D:Delta"[Perl 6 Delta Tablet] *"E:Best of"[Best Of Perl 6 Tablet]* "F:Links"[Perl 6 Links Tablet] "G:Glossary"[Perl 6 Glossary Tablet]
----
{toc: }
This is a small tour, showing the best features and improvements of Perl 6 in short examples, compared to similar working Perl 5 examples.
^^^ Command Line
"Making output"{link: [Perl 6 IO Tablet]Command Line} will become simpler and easier for newbies.
.pre
Perl 5 Perl 6
print "bananas are good\n"; say "bananas are good";
print "and I said: $quotes{\"me\"}\n"; say "and I said: %quotes{"me"}.";
print "and I said: $quotes{\"me\"}\n"; say "and I said: %quotes<me>.";
print "What is ... "; $result = prompt "What is ... ";
chomp($result = <>);
.pre
^^^ File IO
File::Slurp is in the Perl 6 core language and "file reading"{link: [Perl 6 IO Tablet]File} is simpler then ever (and autochomp included).
.pre
Perl 5 Perl 6
$content = do { local $/; $content = slurp "poetry.txt";
open my $FH, "poetry.txt"; <$FH>
};
chomp(@content = do { @content = lines "poetry.txt";
open my $FH, "poetry.txt"; <$FH>
});
.pre
^^^ Automatic multithreading
Applying operations to junctions and arrays is now syntactically compact and readable. Perl 6 will create threads where appropriate to use multiple processors, cores or hyperthreading for high level language SIMD concurrent processing.
.pre
Perl 5 Perl 6
my $sum; my $sum = [+] @numbers;
$sum += $_ for @numbers;
for (0 .. $#factor1) { @product = @factor1 >>*<< @factor2;
$product[$] = $factor1[$] * $factor2[$_];
}
.pre
The Perl 5 code is a simplification, of course Perl6 "does the right thing" when the arrays have different lengths.
^^^ Comparison
Here are junctions, then chained comparison operators.
.pre
Perl 5 Perl 6
if ($a == 3 or $a == 4 or $a == 7) {...} if $a = 3 | 4 | 7 {...}
if (4 < $a and $a < 12) {...} if 4 < $a < 12 {...}
if (4 < $a and $a <= 12) {...} if $a ~~ 4^..12 {...}
$a = defined $b ? $b : $c; $a = $b // $c;
.pre
The defined-OR operator eases lot of cases where Perl 5 newbies could fall into traps.
^^^ Case construct
.pre
Perl 5 Perl 6
given $a {
if ($a == 2 or $a == 5) {...} }} when 2 | 5 {...}
elsif ($a == 6 or $a == 7 or $a == 8 or $a == 9) {} when 6 .. 9 {...}
elsif ($a =~ /g/) {...} when 'g' {...}
else {...} default {...}
}
.pre
"That new construct"{link: [Perl 6 Block Tablet]given} (backported to 5.10) is clear to read, very versatile and when used in combination with junctions, becomes even clearer.
^^^ Powerful for loops
"List iteration via for"{link: [Perl 6 Block Tablet]for} is now much more versatile.
.pre
Perl 5 Perl 6
for my $i (0..15) {...} for ^16 -> $i {...}
for (my $i=15; $i>1; $i-2) {...} for 15,*-2...1 -> $i {...}
for my $key (keys %hash) { for %hash.kv -> $key, $value {
print "$key => $hash{$key}\n"; ... say "$key => $value"; ...
for my $i (0..$#a) { for zip(@a; @b; @c) -> $a, $b, $c {...}
my $a = @a[$i];
my $b = @b[$i];
my $c = @c[$i]; ...
.pre
^^^ Named parameters in subroutines
.pre
Perl 5 Perl 6
sub routine { sub routine ($a, $b, *@rest) {...}
my $a = shift;
my $b = shift;
my @rest = @_;
}
.pre
^^^ Objects with auto generated new and getters and setters
Simple Object creation is now as easy as it gets.
.pre
Perl 5 Perl 6
package Heart::Gold; class Heart::Gold {
has $.speed;
sub new { method stop { $.speed = 0 }
bless {speed => 0 }, shift; }
}
my Heart::Gold $hg1 .= new;
sub speed { $hg1.speed = 100;
my $self = shift; my $hg2 = $hg1.clone;
my $speed = shift;
if (defined $speed) { $self->{speed} = $speed }
else { $self->{speed} }
}
sub stop {
my $self = shift;
$self->{speed} = 0;
}
.pre
The new, getter, setter and clone methods are auto generated. Methods now are called "method".
----
"Intro"[Perl 6 Intro Tablet] - _Chapter:_ "0:History"[Perl 6 History Tablet] "1:Design"[Perl 6 Language Design Tablet] "2:Basics"[Perl 6 Basics Tablet] "3:Var"[Perl 6 Variable Tablet] "4:Op"[Perl 6 Operator Tablet] "5:IO"[Perl 6 IO Tablet] "6:{}"[Perl 6 Block Tablet] "7:Sub"[Perl 6 Subroutine Tablet] "8:OOP"[Perl 6 OOP Tablet] "9:Rx"[Perl 6 Regex Tablet] "10:Meta"[Perl 6 Meta Tablet]
"Overview"[Perl 6 Tablets] - _Appendices:_ "A:Index"[Perl 6 Index Tablet] "B:Tables"[Perl 6 Lookup Tablet] "C:Cook"[Perl 6 Cookbook Tablet] "D:Delta"[Perl 6 Delta Tablet] *"E:Best of"[Best Of Perl 6 Tablet]* "F:Links"[Perl 6 Links Tablet] "G:Glossary"[Perl 6 Glossary Tablet]
----
