Perl 6
Perl 6 Variable Tablet: Revision 74
"Overview"[Perl 6 Tablets] - _Chapter:_ "0:Intr"[Perl 6 Intro Tablet], "1:Hist"[Perl 6 History Tablet], "2:Design"[Perl 6 Language Design 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] - _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]
----
{toc: }
_"Allison Randal"<http://allisonrandal.com/>: The most basic building blocks of a programming language are its nouns, the chunks of data that get sucked in, pushed around, altered in various ways, and spat out to some new location._
^ Primary Types
Perl 6 (as Perl 5) knows 3 basic types of variables: "Scalars"{link: Scalar} (single values), "Arrays"{link: Array} (ordered and indexed lists of several values) and "Hashes"{link: Hash} (2 column table, with ID and associated value pairs). They can be easily distinguished, because in front of their name is a special character called "sigil"{link: [Perl 6 Lookup Tablet] Sigils} (latin for sign). Its the $ (similar to S) for Scalars, @ (like an a) for Arrays and a % (kv pair icon) for a Hash. They are now invariant (not changing), which means for instance, an array vaiable starts always with an @, even if you just want a slice of the content. The sigils mark also distinct namespaces, meaning: in one "lexical scope"{link: Scoping} you can have 3 different variables named $stuff, @stuff and %stuff. These sigils "can also be used as an operator"{link: [perl 6 lookup tablet] Contextualizers} to enforce a context in which the following data will be seen.
The fourth namespace where you can store and retrieve something under specified names is the one of "subroutines and alike"{link: Callable}, even if you don't might think of them as variables. It's sigil & has to be used only rarely.
Special namespaces of Perl 5 (often marked with special syntax) like tokens (__PACKAGE__), formats, file or dir handle and builtins are now regular (mostly scalar) variables or routines.
Because variables are (as anything in Perl 6) "objects"[Perl 6 OOP Tablet], they have methods. In fact, "any operator"[Perl 6 Operator Tablet], including these square or curly brackets you get specific array and hash values with, are just methods of a variable object with a fancy name.
The primary sigil can be followed by a secondary sigil, called "twigil, which mostly indicate special scope"{link: Twigils } of that variable.
^^ Scalar
This type is known as a storage room for one value, but it's more like a reference that can point to anything: to values of any data type, to _code_, to _objects_ or to a compound of values like a "pair"{link: Pair}, "junction"{link: [perl 6 operator tablet] junctions}, "array"{link: Array}, "hash"{link: Hash} or "capture"{link: Capture}. The scalar context is now called item context hence the _scalar_ instruction from Perl 5 was renamed to "item"{link: [perl 6 lookup tablet] Contextualizers}.
> $CHAPTER = 3;
> $pi = 3.14159_26535_89793; # the underscores just ease reading
> $float = 6.02e23;
> $complex = 1+2i;
> $text = 'Welcome all!'; # "single quoted string"{link: [perl 6 IO tablet] Single Quotes}
> $text = {{"}} What is $pi?{{"}}; # "double quoted string"{link: [perl 6 IO tablet] Double Quotes}, does eval $pi to its content
> $text = q:to'EOT'; # "heredoc string"{link: [perl 6 IO tablet] Heredocs}
>> handy for multiline text
>> like HTML templates or email
> EOT
> $handle = open $file_name; # "file handle"{link: [perl 6 IO tablet] Files}
> $object = Class::Name.new();
> $arrayref = {{[0,1,1,2,3,5,8,13,21];}}
> $hashref = {'audreyt'=>'pugs', 'pm'=>'pct', 'damian'=>'larrys evil henchman'};
> $coderef = sub { do_something_completely_diffenent(@_) };
Unlike Perl 5, references are automatically dereferenced to a fitting context. So you could use these $arrayref and $hashref in same way as an array or hash, making $ the variable highlighter, pretty much like in PHP.
^^ Array
is an ordered and indexed list of "scalar variables"{link: Scalar}. If not specified otherwise, they can be changed, prolonged and shorten anytime and used as a list, stack, queue and much more. As in Haskell, lists are processed lazily, which means: the compiler looks only at the part he currently needs. This way Perl 6 can handle infinite lists or do computation on lists that are still building up. The _lazy_ command enforces and the _eager_ command prevents that behaviour on any expression.
The list context is forced with a "@ operator or _list()_ command"{link: [perl 6 lookup tablet] Contextualizers}. That's not autoflattening like in Perl 5 (automatically convert a List of Lists into one List). If you still want that, "say flat(). Or say lol()"{link: [perl 6 lookup tablet] Contextualizers} to explicitly prevent autoflattening.
.pre
@primes = (2,3,5,7,11,13,17,19,23); # an array gets filled
@primes = 2,3,5,7,11,13,17,19,23 ; # same thing, since () just do group
@primes = <2 3 5 7 11 13 17 19 23>; # dito, <> is the new qw()
$arrayref = 2,3,5,7,11,13,17,19,23; # in scalar context you get automatically a reference
$arrayref = 13,; # comma is the new array generator
@primes = 2; # array with one element
@primes = [2,3,5,7,11,13,17,19,23]; # array with one element (arrayref)
@dev = {'dan' => 'parrot'}; # array with one element (hashref)
@data = [1..5],[6..10],[11..15]; # Array of Arrays (AoA)
.pre
^^^ Array Slices
.pre
@primes # all values
"@primes[]" # insert all values in a string, use [] as distinction from mail adresses
$prime = @primes[0]; # get the first prime
$prime = @primes[*-1]; # get the last one
@some = @primes[2..5]; # get several
$cell = @data[1][2]; # get 8, third value of second value (list)
$cell = @data[1;2]; # same thing, shorten syntax
@numbers = @data[1]; # get a copy of the second subarray (6..10)
@copy = @data; # copy the whole AoA, no more reference passing, use binding instead
.pre
^^^ Array Methods
Some of the more important things you can do with lists. All the methods can also used like ops in "elems @rray;"
.pre
? @rray; # boolean context, Bool::True if array has any value in it, even if its a 0
+ @rray; # numeric context, number of elements (like in Perl 5 scalar @a)
@rray.elems; # does the same
@rray.end; # number of the last element, equal to @rray.elems-1
~ @rray; # string context, you get content of all cells, stringified and joined
@rray.cat; # does the same
@rray.join(''); # also same result, you can put another string as parameter that gets between all values
@rray.unshift; # prepend one value to the array
@rray.shift; # remove the first value and return it
@rray.push; # add one value on the end
@rray.pop; # remove one value from the end and return it
@rray.splice($pos,$n)# remove on $pos $n values and replace them with values that follow that two parameter
@rray.delete(@ind); # delete all cell with indecies of @ind
@rray.exists(@ind); # Bool::True if all indecies of @ind have a value (can be 0 or '')
@rray.pick([$n]); # return $n (default is 1) randomly selected values, without duplication
@rray.roll([$n]); # return $n (default is 1) randomly selected values, duplication possible (like roll dice)
@rray.reverse; # all elements in reversed order
@rray.rotate($n); # returns a list where $n times first item is taken to last position if $n is positive, if negative the other way around
@rray.sort($coderef);# returns a sorted list by a userdefined criteria, default is alphanumerical sorting
@rray.min; # numerical smallest value of that array
@rray.max; # numerical largest value of that array
$a,$b= @rray.minmax; # both at once, like in .sort . min or .max a sorting algorith can be provided
@rray.map($coderef); # high oder map function, runs $coderef with every value as $_ and returns the list or results
@rray.classify($cr); # kind of map, but creates a hash, where keys are the results of $cr and values are from @rray
@rray.grep({$_>1}); # high order grep, returns only these elements that pass a condition ($cr returns something positive)
@rray.first($coder); # kind of grep, return just the first matching value
@rray.zip; # join arrays by picking first element left successively from here and then there
.pre
There is even a whole class of metaoperators that work upon lists.
^^ Hash
is in Perl 6 an unordered list of Pairs. "A Pair"{link: Pair} is a single key => value association and "appears in many places"{link: [Perl 6 Language Design Tablet] Maximum reusage} of the language syntax.
.pre
%dev = 'pugs'=>'audreyt', 'pct'=>'pm', "STD"=>'larry';
%dev = :rakudo('jnthn'), :testsuite('moritz'); # adverb (pair) syntax works as well
%dev = ('audreyt', 'pugs', 'pm', 'pct', 'larry', "STD"); # lists get autoconverted in hash context
%compiler = Parrot => {Rakudo => 'jnthn'}, SMOP => {Mildew => 'ruoso'}; # hash of hashes (HoH)
.pre
^^^ Hash Slices
.pre
my $table = %dev; # nicely formatted 2 column table using \t and \n
say %dev; # only $key and $value are separated by \t
~ %dev # string context, same thing
? %dev # bool context, true if hash has any pairs
+ %dev # numeric context, returns number of pairs(keys)
$value = %dev{'key'}; # just give me the value related to that key, like in P5
$value = %dev<pm>; # <> autoquotes like qw() in P5
$value = %dev<<$name>>; # same thing, just with eval
@values = %dev{'key1', 'key2'};
@values = %dev<key1 key2>;
@values = %dev<<key1 key2 $key3>>;
%dev\ .{'patrick'}; # "long dot style", because its its an object in truth
%dev {'audrey'}; # error, only syntax before will work
%dev\ {'allison'}; # works,
%dev .<dukeleto>; # error
%compiler<Parrot><Rakudo>; # value in a HoH, returns 'jnthn'
%compiler<SMOP>; # returns the Pair: Mildew => 'ruoso'
.pre
^^^ Hash Methods
.pre
%dev.keys # returns the list with all keys
%dev.values # list of all values
%dev.kv # flat list with key1, value1, key 2 ...
%dev.pairs # list of pair objects, list context default (same as in @a = %dev)
%dev.invert # reverse all key => value relations
.pre
^^ Callable
Internally "subroutines"[Perl 6 Subroutine Tablet], "methods"[Perl 6 OOP Tablet] and alike are variables with the sigil "&" and stored in a fourth namespace. They are no more builtins with an own namespace, that can't be overwritten or augmented with your programming.
^ Object Types
For a Perl beginner it's enough to know about the everywhere visible, "primary 4 variable types"{link: Primary Types}. However Perl 6 knows about "many more types"{link: [Perl 6 Lookup tablet] object types}, that are organized internally as classes or roles. You can explicitly assign one of these types to you scalar, array or hash variable.
^^ Typing
^^ Pair
are very new and their syntax is used nearly everywhere in the language, where you have associations between a name and a value.
.pre
$pair = 'jakub' => 'helena'; # "=>" is the pair constructor
$pair = :jakub('helena'); # same in adverbial notation
$pair = :jakub<helena>; # same using <>, the new qw()
$pair.key # returns 'jakub'
$pair.value # returns 'helena'
$pair.isa(Pair) # Bool::True
.pre
^^ Capture
also a new type, that can hold all or a part of the parameters a routine gets. Because Perl knows now positional as well as named parameters, it es some mixture of a list and array.
.pre
$cap = \(@a,$s,%h); # creating a capture
| $cap # flatten into argument list (hash like context)
|| $cap # flatten into semicolon list (array like context)
.pre
One important difference between a compound structure of lists and hashes and a capture: while "assignments"{link: Assignment} with = the complete content of the named variables will be copied. But not so in the case of a capture. When I change $s in the last example, the content of $cap changes too, because when parameters to a routine are variables, they are also interpolated in the moment the routine is called, not when its defined.
^ Properties and Traits
^^ Properties
^^ Traits
^ Scoping
"scope declarator"{link: [perl 6 lookup tablet] scope declarator}, "scopes"{link: [perl 6 lookup tablet] scopes }
^^ Twigils
^ Assignment and Binding
^^ Assignment
^^ Binding
^ Special Variables
"are listed heir table"{link: [Perl 6 Lookup Tablet] special variables}. To understand their secondary sigil "look here"{link: Twigils}
----
"Overview"[Perl 6 Tablets] - _Chapter:_ "0:Intr"[Perl 6 Intro Tablet], "1:Hist"[Perl 6 History Tablet], "2:Design"[Perl 6 Language Design 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] - _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]
----
----
{toc: }
_"Allison Randal"<http://allisonrandal.com/>: The most basic building blocks of a programming language are its nouns, the chunks of data that get sucked in, pushed around, altered in various ways, and spat out to some new location._
^ Primary Types
Perl 6 (as Perl 5) knows 3 basic types of variables: "Scalars"{link: Scalar} (single values), "Arrays"{link: Array} (ordered and indexed lists of several values) and "Hashes"{link: Hash} (2 column table, with ID and associated value pairs). They can be easily distinguished, because in front of their name is a special character called "sigil"{link: [Perl 6 Lookup Tablet] Sigils} (latin for sign). Its the $ (similar to S) for Scalars, @ (like an a) for Arrays and a % (kv pair icon) for a Hash. They are now invariant (not changing), which means for instance, an array vaiable starts always with an @, even if you just want a slice of the content. The sigils mark also distinct namespaces, meaning: in one "lexical scope"{link: Scoping} you can have 3 different variables named $stuff, @stuff and %stuff. These sigils "can also be used as an operator"{link: [perl 6 lookup tablet] Contextualizers} to enforce a context in which the following data will be seen.
The fourth namespace where you can store and retrieve something under specified names is the one of "subroutines and alike"{link: Callable}, even if you don't might think of them as variables. It's sigil & has to be used only rarely.
Special namespaces of Perl 5 (often marked with special syntax) like tokens (__PACKAGE__), formats, file or dir handle and builtins are now regular (mostly scalar) variables or routines.
Because variables are (as anything in Perl 6) "objects"[Perl 6 OOP Tablet], they have methods. In fact, "any operator"[Perl 6 Operator Tablet], including these square or curly brackets you get specific array and hash values with, are just methods of a variable object with a fancy name.
The primary sigil can be followed by a secondary sigil, called "twigil, which mostly indicate special scope"{link: Twigils } of that variable.
^^ Scalar
This type is known as a storage room for one value, but it's more like a reference that can point to anything: to values of any data type, to _code_, to _objects_ or to a compound of values like a "pair"{link: Pair}, "junction"{link: [perl 6 operator tablet] junctions}, "array"{link: Array}, "hash"{link: Hash} or "capture"{link: Capture}. The scalar context is now called item context hence the _scalar_ instruction from Perl 5 was renamed to "item"{link: [perl 6 lookup tablet] Contextualizers}.
> $CHAPTER = 3;
> $pi = 3.14159_26535_89793; # the underscores just ease reading
> $float = 6.02e23;
> $complex = 1+2i;
> $text = 'Welcome all!'; # "single quoted string"{link: [perl 6 IO tablet] Single Quotes}
> $text = {{"}} What is $pi?{{"}}; # "double quoted string"{link: [perl 6 IO tablet] Double Quotes}, does eval $pi to its content
> $text = q:to'EOT'; # "heredoc string"{link: [perl 6 IO tablet] Heredocs}
>> handy for multiline text
>> like HTML templates or email
> EOT
> $handle = open $file_name; # "file handle"{link: [perl 6 IO tablet] Files}
> $object = Class::Name.new();
> $arrayref = {{[0,1,1,2,3,5,8,13,21];}}
> $hashref = {'audreyt'=>'pugs', 'pm'=>'pct', 'damian'=>'larrys evil henchman'};
> $coderef = sub { do_something_completely_diffenent(@_) };
Unlike Perl 5, references are automatically dereferenced to a fitting context. So you could use these $arrayref and $hashref in same way as an array or hash, making $ the variable highlighter, pretty much like in PHP.
^^ Array
is an ordered and indexed list of "scalar variables"{link: Scalar}. If not specified otherwise, they can be changed, prolonged and shorten anytime and used as a list, stack, queue and much more. As in Haskell, lists are processed lazily, which means: the compiler looks only at the part he currently needs. This way Perl 6 can handle infinite lists or do computation on lists that are still building up. The _lazy_ command enforces and the _eager_ command prevents that behaviour on any expression.
The list context is forced with a "@ operator or _list()_ command"{link: [perl 6 lookup tablet] Contextualizers}. That's not autoflattening like in Perl 5 (automatically convert a List of Lists into one List). If you still want that, "say flat(). Or say lol()"{link: [perl 6 lookup tablet] Contextualizers} to explicitly prevent autoflattening.
.pre
@primes = (2,3,5,7,11,13,17,19,23); # an array gets filled
@primes = 2,3,5,7,11,13,17,19,23 ; # same thing, since () just do group
@primes = <2 3 5 7 11 13 17 19 23>; # dito, <> is the new qw()
$arrayref = 2,3,5,7,11,13,17,19,23; # in scalar context you get automatically a reference
$arrayref = 13,; # comma is the new array generator
@primes = 2; # array with one element
@primes = [2,3,5,7,11,13,17,19,23]; # array with one element (arrayref)
@dev = {'dan' => 'parrot'}; # array with one element (hashref)
@data = [1..5],[6..10],[11..15]; # Array of Arrays (AoA)
.pre
^^^ Array Slices
.pre
@primes # all values
"@primes[]" # insert all values in a string, use [] as distinction from mail adresses
$prime = @primes[0]; # get the first prime
$prime = @primes[*-1]; # get the last one
@some = @primes[2..5]; # get several
$cell = @data[1][2]; # get 8, third value of second value (list)
$cell = @data[1;2]; # same thing, shorten syntax
@numbers = @data[1]; # get a copy of the second subarray (6..10)
@copy = @data; # copy the whole AoA, no more reference passing, use binding instead
.pre
^^^ Array Methods
Some of the more important things you can do with lists. All the methods can also used like ops in "elems @rray;"
.pre
? @rray; # boolean context, Bool::True if array has any value in it, even if its a 0
+ @rray; # numeric context, number of elements (like in Perl 5 scalar @a)
@rray.elems; # does the same
@rray.end; # number of the last element, equal to @rray.elems-1
~ @rray; # string context, you get content of all cells, stringified and joined
@rray.cat; # does the same
@rray.join(''); # also same result, you can put another string as parameter that gets between all values
@rray.unshift; # prepend one value to the array
@rray.shift; # remove the first value and return it
@rray.push; # add one value on the end
@rray.pop; # remove one value from the end and return it
@rray.splice($pos,$n)# remove on $pos $n values and replace them with values that follow that two parameter
@rray.delete(@ind); # delete all cell with indecies of @ind
@rray.exists(@ind); # Bool::True if all indecies of @ind have a value (can be 0 or '')
@rray.pick([$n]); # return $n (default is 1) randomly selected values, without duplication
@rray.roll([$n]); # return $n (default is 1) randomly selected values, duplication possible (like roll dice)
@rray.reverse; # all elements in reversed order
@rray.rotate($n); # returns a list where $n times first item is taken to last position if $n is positive, if negative the other way around
@rray.sort($coderef);# returns a sorted list by a userdefined criteria, default is alphanumerical sorting
@rray.min; # numerical smallest value of that array
@rray.max; # numerical largest value of that array
$a,$b= @rray.minmax; # both at once, like in .sort . min or .max a sorting algorith can be provided
@rray.map($coderef); # high oder map function, runs $coderef with every value as $_ and returns the list or results
@rray.classify($cr); # kind of map, but creates a hash, where keys are the results of $cr and values are from @rray
@rray.grep({$_>1}); # high order grep, returns only these elements that pass a condition ($cr returns something positive)
@rray.first($coder); # kind of grep, return just the first matching value
@rray.zip; # join arrays by picking first element left successively from here and then there
.pre
There is even a whole class of metaoperators that work upon lists.
^^ Hash
is in Perl 6 an unordered list of Pairs. "A Pair"{link: Pair} is a single key => value association and "appears in many places"{link: [Perl 6 Language Design Tablet] Maximum reusage} of the language syntax.
.pre
%dev = 'pugs'=>'audreyt', 'pct'=>'pm', "STD"=>'larry';
%dev = :rakudo('jnthn'), :testsuite('moritz'); # adverb (pair) syntax works as well
%dev = ('audreyt', 'pugs', 'pm', 'pct', 'larry', "STD"); # lists get autoconverted in hash context
%compiler = Parrot => {Rakudo => 'jnthn'}, SMOP => {Mildew => 'ruoso'}; # hash of hashes (HoH)
.pre
^^^ Hash Slices
.pre
my $table = %dev; # nicely formatted 2 column table using \t and \n
say %dev; # only $key and $value are separated by \t
~ %dev # string context, same thing
? %dev # bool context, true if hash has any pairs
+ %dev # numeric context, returns number of pairs(keys)
$value = %dev{'key'}; # just give me the value related to that key, like in P5
$value = %dev<pm>; # <> autoquotes like qw() in P5
$value = %dev<<$name>>; # same thing, just with eval
@values = %dev{'key1', 'key2'};
@values = %dev<key1 key2>;
@values = %dev<<key1 key2 $key3>>;
%dev\ .{'patrick'}; # "long dot style", because its its an object in truth
%dev {'audrey'}; # error, only syntax before will work
%dev\ {'allison'}; # works,
%dev .<dukeleto>; # error
%compiler<Parrot><Rakudo>; # value in a HoH, returns 'jnthn'
%compiler<SMOP>; # returns the Pair: Mildew => 'ruoso'
.pre
^^^ Hash Methods
.pre
%dev.keys # returns the list with all keys
%dev.values # list of all values
%dev.kv # flat list with key1, value1, key 2 ...
%dev.pairs # list of pair objects, list context default (same as in @a = %dev)
%dev.invert # reverse all key => value relations
.pre
^^ Callable
Internally "subroutines"[Perl 6 Subroutine Tablet], "methods"[Perl 6 OOP Tablet] and alike are variables with the sigil "&" and stored in a fourth namespace. They are no more builtins with an own namespace, that can't be overwritten or augmented with your programming.
^ Object Types
For a Perl beginner it's enough to know about the everywhere visible, "primary 4 variable types"{link: Primary Types}. However Perl 6 knows about "many more types"{link: [Perl 6 Lookup tablet] object types}, that are organized internally as classes or roles. You can explicitly assign one of these types to you scalar, array or hash variable.
^^ Typing
^^ Pair
are very new and their syntax is used nearly everywhere in the language, where you have associations between a name and a value.
.pre
$pair = 'jakub' => 'helena'; # "=>" is the pair constructor
$pair = :jakub('helena'); # same in adverbial notation
$pair = :jakub<helena>; # same using <>, the new qw()
$pair.key # returns 'jakub'
$pair.value # returns 'helena'
$pair.isa(Pair) # Bool::True
.pre
^^ Capture
also a new type, that can hold all or a part of the parameters a routine gets. Because Perl knows now positional as well as named parameters, it es some mixture of a list and array.
.pre
$cap = \(@a,$s,%h); # creating a capture
| $cap # flatten into argument list (hash like context)
|| $cap # flatten into semicolon list (array like context)
.pre
One important difference between a compound structure of lists and hashes and a capture: while "assignments"{link: Assignment} with = the complete content of the named variables will be copied. But not so in the case of a capture. When I change $s in the last example, the content of $cap changes too, because when parameters to a routine are variables, they are also interpolated in the moment the routine is called, not when its defined.
^ Properties and Traits
^^ Properties
^^ Traits
^ Scoping
"scope declarator"{link: [perl 6 lookup tablet] scope declarator}, "scopes"{link: [perl 6 lookup tablet] scopes }
^^ Twigils
^ Assignment and Binding
^^ Assignment
^^ Binding
^ Special Variables
"are listed heir table"{link: [Perl 6 Lookup Tablet] special variables}. To understand their secondary sigil "look here"{link: Twigils}
----
"Overview"[Perl 6 Tablets] - _Chapter:_ "0:Intr"[Perl 6 Intro Tablet], "1:Hist"[Perl 6 History Tablet], "2:Design"[Perl 6 Language Design 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] - _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]
----
