Intro Chapter: 0. History 1. Design 2. Basic 3. Var 4. Op 5. IO 6. Block 7. Sub 8. OOP 9. Regex 10. Meta
Overview Appendix: A. Index B. Grouped C. Classtree D. Delta E. Exciting F. FAQ G. Glossary H. Href

Variables

Sigils

All variables in Perl begin with a sigil. They mark the 3 primary var types. The 4th sigil is for callables (routines) and the 5th is for boxes (namespaces) that organize the previous 4.

`$`	scalar, single value, can be of any data type
`@`	ordered array, indexed list of scalar
`%`	unordered hash (associative array), 2 column table with unique IDs (keys) and associated values (value)
`&`	code/rule/token/regex
`::`	abstraction: package/module/class/role/subset/enum/type/grammar

The first 4 can also be used as prefix operators, called contextualizers, that force different contexts, but there are much more different contexts then 4.

Twigils

Twigil is short for secondary sigil. They follow after a primary sigil and mark special namespaces or variables with special meanings and properties.

`$foo`	ordinary scoping (no twigil)
`$.foo`	object attribute public accessor
`$!foo`	object attribute private storage
`$^foo`	self-declared formal positional parameter
`$:foo`	self-declared formal named parameter
`$*foo`	contextualizable global variable
`$?foo`	compiler hint variable
`$=foo`	pod variable
`$~foo`	the foo sublanguage seen by the parser at this lexical spot

Special Variables

`$_`	context variable
`$!`	error msg

Match Variables

`$/`	last created match object of this scope with these methods
`$<...>`	alias to named capture, i.e., / < ... > or/{'...'}
`$0 ...`	alias to positional capture, like in P5 - `$1 .. $9` but doesn't stop at `$9`
`@()`	array that holds $0 .. $9 and rest and positional submatches

Global Variables

context variable, default global (run time), any of them are now objects with several methods

`@*ARGS`	Arguments (Parameter) to a program (script), formerly @ARGV
`$*ARGFILES`	magic command-line input handle
`$*IN`	standard input handle (command line mostly)
`$*OUT`	standard output (command line mostly)
`$*ERR`	standard error output (command line mostly)
`$*CWD`	current working directory (Str)
`@*INC`	include pathes (but not for std library modules), formerly @INC
`$*LANG`	LANG variable from `%*ENV` that defines what human language is used
`%*ENV`	system environment variables, formerly %ENV
`%*OPTS`	options from command line
`$*TZ`	local time zone
`$*EXECUTABLE_NAME`	former $0
`$*PERL`	perl version running under, was formerly `$^V` or `$]`
`$*KERNEL`	operating system running under
`$*DISTRO`	OS distribution am I running under
`$*PID`	ID of the running process,
`$*GID`	real global ID of the running process owner, formerly @(
`$*UID`	real user ID of the running process owner (user), formerly @<
`$*EGID`	effective global ID, formerly @)
`$*EUID`	effective user ID, formerly @>
$*ON_DIE	exception handler, run befor die, formerly `$SIG{__DIE__}`
$*ON_WARN	exception handler, run befor warn, formerly `$SIG{__WARN__}`
$*COMPILING
$*EMERGENCY_MEMORY	formerly `$^M`
$*DEBUGGING

Compiler Hint Variables

compiler constants (fixed at compile time)

`$?KERNEL`	for which operating System was this program compiled?
`$?DISTRO`	Which OS distribution am I compiling under?
`$?VM`	Which virtual machine am I compiling under
`$?XVM`	Which virtual machine am I cross-compiling for
`$?PERL`	Which Perl am I compiled for?
`$?ENC`	current encoding
`$?NF`	default string normalization method
`%?LANG`	Hash of Grammar # What is the current set of interwoven languages?
`$?GRAMMAR`	current grammar
`$?FILE`	current filename of source file (FILE in P5)
`$?MODULE`	current module
`$?PACKAGE`	current package (PACKAGE)
`$?CLASS`	current class
`::?CLASS`	current class (as package name)
`$?ROLE`	current role (as variable)
`::?ROLE`	current role (as package or type name)
`&?ROUTINE`	current sub or method (SUB)
`&?BLOCK`	reference to current block
`$?LINE`	current line number (LINE)
`$?TABSTOP`

POD Variables

File-scoped POD data

`$=pod`	surrounding POD object
`$=data`	data block handle (=begin DATA ... =end)
`@=COMMENT`	All the comment blocks in the file

Slang Variables

sublanguage seen by the parser at this lexical spot

`$~MAIN`	the current main language (e.g. Perl statements)
`$~Quote`	the current root of quoting language
`$~Quasi`	the current root of quasiquoting language
`$~Regex`	the current root of regex language
`$~Trans`	the current root of transliteration language
`$~P5Regex`	the current root of the Perl regex language

Constants

are builtins (not exactly variables and without a sigil) that return always the same important value

Name	Value	Meaning
e	2.71828182878434	euler number
i	0+1i	imaginary number
pi	3.14159265394248	ratio of a circle's circumference to its diameter

Scope

Scopes

The following pseudo-package names are reserved at the front of a name:

MY	Symbols in the current lexical scope (aka $?SCOPE)
OUR	Symbols in the current package (aka $?PACKAGE)
CORE	Outermost lexical scope, definition of standard Perl
GLOBAL	Interpreter-wide package symbols, really CORE::GLOBAL
PROCESS	Process-related globals (superglobals), CORE::PROCESS
COMPILING	Lexical symbols in the scope being compiled
DYNAMIC	Contextual symbols in my or any caller's lexical scope

The following relative names are also reserved but may be used anywhere in a name:

CALLER	Contextual symbols in the immediate caller's lexical scope
OUTER	Symbols in the next outer lexical scope
UNIT	Symbols in the outermost lexical scope of compilation unit
SETTING	Lexical symbols in the unit's DSL (usually CORE)
PARENT	Symbols in this package's parent package (or lexical scope)

The following is reserved at the beginning of method names in method calls:

SUPER

Package symbols declared in inherited classes

Declarator

`my`	introduces lexically scoped names
`state`	introduces lexically scoped but persistent names
`our`	introduces package-scoped names
`anon`	introduces names that aren't to be stored anywhere
`has`	introduces object attribute names
`augment`	adds definitions to an existing name
`supersede`	replaces definitions of an existing name

Value Types

In Perl 6 any variable and value is an object. Here's a list of all different types of values, represented my different classes or roles. The routine types are in a different section.

Undefined types

Mu	Most Undefined
Junction	unordered superposition of data with and/or/one/none
Each	ordered superposition (conjectural)
Failure	Failure (lazy exceptions, thrown if not handled properly)
Any	Perl 6 object (default routine parameter type, excludes junction)
Cool	Perl 6 Convenient OO Loopbacks
Whatever	Wildcard (like Any, but subject to do-what-I-mean via MMD)
Int	Any Int object
Widget	Any Widget object

Immutable types

Str	Perl string (finite sequence of Unicode characters)
Bit	Perl single bit (allows traits, aliasing, undef, etc.)
Int	Perl integer (allows Inf/NaN, arbitrary precision, etc.)
Num	Perl number (approximate Real, generally via floating point)
Rat	Perl rational (exact Real, limited denominator)
FatRat	Perl rational (unlimited precision in both parts)
Complex	Perl complex number
Bool	Perl boolean
Exception	Perl exception
Block	executable objects that have lexical scope
Range	a pair of ordered endpoints
Set	unordered collection of values that allows no duplicates
Bag	unordered collection of values that allows duplicates
Enum	an immutable Pair
EnumMap	a mapping of Enums with no duplicate keys
Signature	function parameters (left-hand side of a binding)
Parcel	arguments in a comma list
LoL	arguments in a semicolon list
Capture	function call arguments (right-hand side of a binding)
Blob	an undifferentiated mass of ints, an immutable Buf
Instant	a point on the continuous atomic timeline
Duration	difference between two Instants
HardRoutine	a routine that is committed to not changing

Mutable types

Iterator	Perl list
RangeIter	Iterator over a Range
Scalar	Perl scalar
Array	Perl array
Hash	Perl hash
KeySet	KeyHash of Bool (does Set in list/array context)
KeyBag	KeyHash of UInt (does Bag in list/array context)
Pair	a single key-to-value association
Buf	Perl buffer (a stringish array of memory locations)
IO	Perl filehandle
Routine	base class for all wrappable executable objects
Sub	Perl subroutine
Method	Perl method
Submethod	Perl subroutine acting like a method
Macro	Perl compile-time subroutine
Regex	Perl pattern
Match	Perl match, usually produced by applying a pattern, has these methods
Stash	a symbol table hash (package, module, class, lexpad, etc)
SoftRoutine	a routine that is committed to staying mutable

Low level data types

This is more low level than the last table. These types are more meant to give the compiler optimizing hints.

int1
int2
int4
int8
int16
int32	(aka int on 32-bit machines)
int64	(aka int on 64-bit machines)
int128	(aka int on 128-bit machines)
uint1	(aka bit)
uint2
uint4
uint8	(aka byte)
uint16
uint32
uint64
uint128
num16
num32
num64	(aka num on most architectures)
num128
complex16
complex32
complex64	(aka complex on most architectures)
complex128
rat8
rat16
rat32
rat64
rat128
buf8	aka buf, a "normal" byte buffer
buf16	a uint16 buffer
buf32	a uint32 buffer
buf64	a uint64 buffer

Object Introspection

Every value in P6 is an object and has following methods to tell more about itself.

WHAT	short name of the class that an object belongs to
WHICH	object ID (type)
WHO	package, that support that object, long name in string context
WHERE	memory address of the object
HOW	object of meta class: "Higher Order Workings"
WHEN	(reserved for events?)
WHY	(reserved for documentation)
WHENCE	autovivification of closures

Operators

Table of Precedence

all level of precedence

A	Level	Examples
N	Terms	`42` `3.14` `"eek"` `qq["foo"]` `$x` `:!verbose @$array`
L	Method postfix	`.meth .+ .? .* .() .[] .{} .<> .<<>> .:: .= .^ .:`
N	Autoincrement	`++` `--`
R	Exponentiation	`**`
L	Symbolic unary	`!` `+` `-` `~` `?` `\|` `\|\|` `+^` `~^` `?^` `^`
L	Multiplicative	`*` `/` `%` `%%` `+&` `+<` `+>` `~&` `~<` `~>` `?&` `div` `mod` `gcd` `lcm`
L	Additive	`+` `-` `+\|` `+^` `~\|` `~^` `?\|` `?^`
L	Replication	`x` `xx`
X	Concatenation	`~`
X	Junctive and	`&` `(&)` `∩`
X	Junctive or	`\|` `^` `(\|)` `(^)` `∪` `(-)`
L	Named unary	`sleep` `abs` `sin` `temp` `let`
N	Structural infix	`but` `does` `<=>` `leg` `cmp` `..` `..^ ^.. ^..^`
C	Chaining infix	`!= ==` `<` `<=` `>` `>=` `eq` `ne` `lt` `le` `gt` `ge` `~~` `===` `eqv !eqv`
X	Tight and	`&&`
X	Tight or	`\|\|` `^^` `//` `min` `max`
R	Conditional	`?? !!` `ff` `fff`
R	Item assignment	`=` `=>` `+= -= **= xx= .=`
L	Loose unary	`so` `not`
X	Comma operator	`,` `:`
X	List infix	`Z` `minmax` `X` `X~ X* Xeqv` `...`
R	List prefix	`print` `push` `say` `die` `map` `substr` `...` `[+] [*]` `any` `Z=`
X	Loose and	`and` `andthen`
X	Loose or	`or` `xor` `orelse`
X	Sequencer	`<==` `==>` `<<==` `==>>`
N	Terminator	`;` `{...}` `unless` `extra ) ] }`

Operator Associativity

associativity

	Assoc	`$a <op> $b <op> $c` (infix op)	`<op>$a<op>` (unary op)
L	left	`($a <op> $b) <op> $c`	(`<op>`$a)`<op>`
R	right	`$a <op> ($b <op> $c)`	`<op>`($a `<op>`)
N	non	ILLEGAL	ILLEGAL
C	chain	`($a <op> $b) and ($b <op> $c)`
X	list	`infix:<op>($a; $b; $c)`

Metaoperators

appear mostly before or around regular operators and give them different meaning or greater range. They can be nested like @a X[+=] @b, but be careful with that. In the example V stands for Value, L for left Value, and R for right. A number is the array index. Words in the second column are short explanation or an aliasing method if followed by ().

`op=`	self assign	known from P5, `$L <op>= $R` equals `$L = $L op $R`
`!op`	negation	known from P5, `$L !<op> $R` equals `!($L op $R)`
`Rop`	reverse	reverses the order of the operands
`Sop`	sequence	like reduction, only synchronous, execution in listed order is guaranteed; suppresses any explicit or implicit parallelism
`>>op`	hyper	processes arrays eager and in parallel or applies a single value to all array elements, `@E = $L[0] op $R[0], $L[1] op $R[1], ...;`
`<<op`	hyper	like above, points to the side which determines dimensionality, `@E = $L[0] op $R[0], $L[1] op $R[1], ...;`
`[op]`	reduce()	applies the operator between all elements of an array, `$result = $V[0] op $V[1] op ...;`
`[\op]`	triangle()	applies above reduction to a series of lists made of array slices ranging in length from 1 to the complete length of the original list, `@result = $V[0], $V[0] op $V[1], $V[0] op $V[1] op $V[2], ...;`
`Xop`	crosswith()	performs the operator to all the pairs of the Cartesian product of two arrays; `@result = $L[0] op $R[0], $L[0] op $R[1], $L[1] op $R[0], $L[1] op $R[1]`
`Zop`	zipwith()	like hyper, but evaluates lazy, `@result = $L[0] op $R[0], $L[1] op $R[1], ...`

Unicode operators

The two hyper operators and the evaluating autoquoting can be written with the unicode signs (also documented as "French Quotes") or with double lesser than or greater than signs (documented as "Texas Quotes").

«	<<	Hyperop, right side dictates length of result
»	>>	Hyperop, left side dictates length of result
«»	<< >>	qw with evaluation and quote protection

Contextualizers

prefix operators or functions that forcing a context.

`$()`	item()	scalar/item context
`?`	so()	boolean
`!`	not()	negated bool context
`+`		numeric
`-`		negated num context
`~`		string
`@()`	list()	array/list context
	flat()	flat list
	lol()	list of list (once named slice context)
`%()`	hash()	hash context
`&()`	code()	code
`\|`		flatten capture object into arglist (named parameter)
`\|\|`		flatten capture object into semicolon list (positional parameter)

Junctions

The infix ops in the first columns create junctions by combining two values (can be Junctions itself), the ops in second column are to be applied to a list as prefix op or method.

Junctive Infix Op	Prefix Op	Operation	Meaning
&	all	AND	True if all are True
^	one	XOR	True if exactly one is True
\|	any	OR	True if at least one is True
	none	NOT any	True if none are True

Smartmatch

When ~~ is used as infix $_ is the left side, X is right. In when clauses just X is stated. Selection of the comparison alhorithm (4th column) is based on the value types as stated in the first two columns.

`$_`	X	Type of Match Implied	Match if (given `$_`)
Any	True	`~~` True	(parsewarn)
Any	False	`~~` False match	(parsewarn)
Any	Match	`~~` Successful match	(parsewarn on literal token)
Any	Nil	`~~` Benign failure	(parsewarn on literal token)
Any	Failure	Failure type check	(okay, matches against type)
Any	`*`	block signature match	block successfully binds to `\|$_` (flattened arglist)

Any	Callable:($)	item sub truth	`X($_)`
Any	Callable:()	simple closure truth	`X()` (ignoring `$_`)
Any	Bool	simple truth	`X`
Any	Match	match success	`X`
Any	Nil	benign failure X	(treats Nil value as failure)
Any	Failure	malign failure X	(passes Failure object through)
Any	Numeric	numeric equality	`+$_ == X`
Any	Stringy	string equality	`~$_` eq X
Any	Whatever	always matches	`True`

Associative	Pair	test hash mapping	`$_{X.key} ~~ X.value`
Any	Pair	test object attribute	`?."{X.key}" = ?X.value` (e.g. filetests)

Set	Set	identical sets	`$_` === X
Any	Setty	force set comparison	`$_.Set === X.Set`

Bag	Bag	identical sets	`$_ === X`
Any	Baggy	force bag comparison	`$_.Bag === X.Bag`

Mix	Mix	identical sets	`$_ === X`
Any	Mixy	force mix comparison	`$_.Mix === X.Mix`

Associative	Array	keys/list are comparable	`+X == +$_ and $_{X.all}:exists`
Positional	Array	arrays are comparable	`$_ «===» X` (dwims `*` wildcards!)
Callable	Positional	list vs predicate	`so` `$_(X)`
Any	Positional	lists are comparable	`$_[] «===» X[]`

Hash	Hash	hash mapping equivalent	`$_` `eqv` `X`
Associative	Hash	force hash comparison	`$_.Hash` `eqv` `X`
Pair	Hash	hash does mapping	`X{.key} ~~ .value`
Positional	Hash	attempted any/all	`FAIL, point user to [].any and [].all for LHS`
Callable	Hash	hash vs predicate	`so` `$_(X)`
Any	Hash	hash contains object	`X.{$_}:exists`

Str	Regex	string pattern match	`.match(X)`
Associative	Regex	attempted reverse dwim	`FAIL, point user to any/all vs keys/values/pairs`
Positional	Regex	attempted any/all/cat	`FAIL, point user to any/all/cat/join for LHS`
Any	Regex	pattern match	`.match(X)`

Range	Range	subset range	`!$_ or .bounds.all ~~ X (mod ^'s)`
Any	Range	in real range	`X.min <= $_ <= X.max (mod ^'s)`
Any	Range	in stringy range	`X.min le $_ le X.max (mod ^'s)`
Any	Range	in generic range	`[!after] X.min,$_,X.max` (etc.)

Any	Type	type membership	`$_.does(X)`

Signature	Signature	sig compatibility	`$_` is a subset of X ???
Callable	Signature	sig compatibility	`$_.sig` is a subset of X ???
Capture	Signature	parameters bindable	`$_` could bind to X (doesn't!)
Any	Signature	parameters bindable	`(pipe)$_` could bind to X (doesn't!)

Signature	Capture	parameters bindable	X could bind to $_

Any	Any	scalars are identical	`$_ === X`

Test Methods

Methods of IO::Path replace the Perl 5 filetest ops (like -e). Use it as in $filename.IO ~~ :X or $filename.IO.X.

:r	Bool	Path is readable by effective uid/gid
:w	Bool	Path is writeable by effective uid/gid
:x	Bool	Path is executable by effective uid/gid
:o	Bool	Path is owned by effective uid.

:R	Bool	Path is readable by real uid/gid
:W	Bool	Path is writeable by real uid/gid
:X	Bool	Path is executable by real uid/gid
:O	Bool	Path is owned by real uid.

:e	Bool	Path exists
:s	Int	Path has size greater than zero
:z	Bool	Path has zero size (an empty file).

:f	Bool	Path is a plain file
:d	Bool	Path is a directory
:l	Bool	Path is a symbolic link.
:L	Str	Actual path is a symbolic link (readlink)
:p	Bool	Path is a named pipe (FIFO), or filehandle is a pipe
:S	Bool	Path is a socket
:b	Bool	Path is a block special file
:c	Bool	Path is a character special file

:u	Bool	Path has setuid bit set
:g	Bool	Path has setgid bit set
:k	Bool	Path has sticky bit set

Quoting Ops

The basic quoting operator (Q) does nothing, just taking literally what you quoted as a string. But with several adverbs, it behaves like the well known following ops:

Op	Nonealphanumeric Version	Translated Into Quoting Adverbs	Method Version	Meaning
q//	' '	Q :q //		single, simple nonevaluating quotes
qq//	" "	Q :qq //		double, evaluating quotes
qw//	< >	Q :q :w //		simple autoquotes (spaces divide words)
	<< >>	Q :qq :ww //		evaluating autoquotes with quote protection
qx//		Q :q :x //		command execution (system call) without evaluation
qqx//		Q :qq :x //		command execution (system call) with evaluation
qp//		Q :q :p //		paths
rx//		Q :regex //		regex
m//		Q :match // [	.match()](appendix-a-index#match) m	atching
ms//		Q :match :sigspace //		matching, spaces divide words
s///		Q :subst /// [	.subst()](appendix-a-index#subst) s	ubstitution
ss///		Q :subst :samespace /// &	nbsp; su	bstitution, spaces divide words
tr///		Q :trans /// [	.trans()](appendix-a-index#trans) [	transliteration](appendix-g-glossary#transliteration)
quasi {}		Q :code //		quasiquoting

Text Processing

Quoting Adverbs

There are a lot more adverbs to fine tune your quoting. The Adverbs can used with any quoting operator like: Q :s/.../ or qq :p /.../.

Short	Long	Meaning
:q	:single	interpolate \\ and \'
:qq	:double	interpolate with :s, :a, :h, :f, :c, :b
:s	:scalar	interpolate $ vars
:a	:array	interpolate @ vars
:h	:hash	interpolate % vars
:f	:function	interpolate & calls
:c	:closure	interpolate {...} expressions
:b	:backslash	interpolate \n, \t, etc. (implies :q at least)
:w	:words	split result on words (no quote protection)
:ww	:quotewords	split result on words (with quote protection)
:p	:path	return a path object (see S16 for more options)
:to	:heredoc	rarse result as heredoc terminator
:x	:exec	execute as command and return results
	:code	quasiquoting
	:regex	parse as regex
	:subst	parse as substitution
	:trans	parse as transliteration

Regex Modifier

Stay behind the regex op and change the behaviour of the regex, its search scope, etc. Most can also also put inside a subregex (in brackets).

Short	Long	Meaning
:g	:global	searches for any finding
:x(n)		searches n times (n is an int)
:nth(n)	:st :nd :rd	demands the nth finding, has many aliases for correct spelling (:2nd)
:c(n)	:continue	searches from nth position (counting from 0)
:p(n)	:pos	searches only on nth position (counting from 0)
:ov	:overlap	searches on all positionens just one time (activates backtracking)
:ex	:exhaustive	searches on all positions as long as it findes something (activates backtracking)
	:ratchet	deactivates backtracking
	:panic	overwriting of possible set :ratchet for all subrules (activates backtracking)
	:keepall	subrules have to memorize everything
:rw		the regex has the right to change the string
:s	:sigspace	whitespace just separate parts of the Regex, don't stand for spaces to look for
:ss	:samespace	as in :s for substitutions, 1st part replaced with 1st part in second half a.s.o. (ss/teh hsa/the has/;)
:i	:ignorecase	no distinctions between uppercase and lowercase
:ii	:samecase	substitute with chars of same case as the matching
:m	:ignoremark	comparing base characters (Unicode non-mark characters) while ignoring any trailing mark characters
:mm	:samemark	substitute with chars that has same mark/accent pattern as the matched string
	:bytes	searches on byte level
	:chars	searches on character level (default)
	:codes	matches between codepoints
	:graphs	match language-independent graphemes
:P5	:Perl5	use the Perl 5 Regex syntax

Regex Metacharacter

`.`	any character
`^`	begin of the sring
`^^`	begin of a line
`$`	end of the string
`$$`	end of a line
`(...)`	group patterns and capture the result
`[...]`	group patterns without capturing
`{...}`	execute a closure (Perl 6 code) within a rule
`<...>`	match a subrule (assertion
`\|`	match alternate patterns (logical OR with LTM)
`\|\|`	match alternate patterns (sequential OR)
`&`	match multiple patterns (AND)
`**`	muliply this (meta)char/subrule times the following digit on right side
`%`	match this (meta)char/subrule as long as separated by (meta)char/subrule on the right
`%%`	like %, but allows trailing separator
`\`	escape a metacharacter to get a literal character, or escape a literal character to get a metacharacter
`#`	mark a comment (to the end of the line)
`:=`	bind the result of a match to a hypothetical variable

Quantifier

`?` zero	or one
`+` one o	r more
`*` zero	or more
`**` maxim	al greedy matching
`**` mulip	ly this (meta)char/subrule times the following digit on right side
`**?` minim	al matching
`%` match	this (meta)char/subrule as long as separated by (meta)char/subrule on the right
`%%` like	%, but allows trailing separator

Control Chars

These Escape Sequences will be evaluated inside quotes to invisible control chars, if the ":b" aka ":backslash" quoting Adverbs is set (included in :quotewords and :double). They are also usable in regexes and thatswhy also included in the next list.

`\a`	BELL
`\b`	BACKSPACE
`\e`	ESCAPE
`\f`	FORM FEED
`\n`	LINE FEED
`\r`	CARRIAGE RETURN
`\t`	TAB

Escape Sequences

To be used just inside of regexes (rx/.../, m/.../, s/.../.../ and tr/.../.../).

`\0[ ... ]`	character given in octal (brackets optional)
`\c[ ... ]`	named character or control character
`\C[ ... ]`	any character except the bracketed named or control character
`\d`	digit
`\D`	nondigit
`\e`	escape character
`\E`	anything but an escape character
`\f`	form feed
`\F`	anything but a form feed
`\n`	(logical) newline
`\N`	anything but a (logical) newline
`\h`	horizontal whitespace
`\H`	anything but horizontal whitespace
`\L[ ... ]`	Everything within the brackets is lowercase
`\Q[ ... ]`	all metacharacters within the brackets match as literal characters
`\r`	return
`\R`	anything but a return
`\s`	any whitespace character, \h or \v
`\S`	anything but whitespace
`\t`	a tab
`\T`	anything but a tab
`\U[ ... ]`	everything within the brackets is uppercase
`\v`	vertical whitespace
`\V`	anything but vertical whitespace
`\w`	word character (Unicode alphanumeric plus "_")
`\W`	anything but a word character
`\x[ ... ]`	character given in hexadecimal (brackets optional)
`\X[ ... ]`	anything but the character given in hexadecimal (brackets optional)

Zero-Width Boundaries

zero-width boundaries begin with a pipe symbol. To negate put a ! in front of the pipe symbol.

`<\|c>`	codepoint boundary (always matches in grapheme/codepoint mode)
`<\|g>`	grapheme boundary (always matches in grapheme mode)
`<\|w>`	word boundary aka <wb>

Subrules

predefined rules (see routine type rule) for any grammar or regex. They can have prefixes: . (dot) marks a non-capturing subrule, ? and ! are also non-capturing positive and negative zero width assertions.

`<alpha>`	single alphabetic character
`<upper>`	uppercase char
`<lower>`	lowercase char
`<digit>`	single digit
`<xdigit>`	hexadecimal digit
`<alnum>`	alphanumeric char, equivalent to <+alpha +digit>
`<punct>`	punctuation char
`<ident>`	an identifier
`<print>`	printable char
`<graph>`	"graphical" char like kanji
`<cntrl>`	a control char
`<blank>`	mostly a space or tab
`<space>`	whitespace character aka
`<ws>`	whitespace, roughly equals
`<wb>`	zero-width word boundary, spot with between and
`<ww>`	zero-width inside word spot between and
`<?before pattern>`	zero-width lookahead
`<!before pattern>`	negative zero-width lookahead, true if the pattern does not match
`<?after pattern>`	zero-width lookbehind
`<!after pattern>`	negative zero-width lookbehind
`<?same>`	zero-width between two identical chars
`<prior>`	last matched pattern
`<?>`	matches nothing, always true
`<!>`	always false

Match Object Methods

can also applied to any positional ($/[2][3].to) and named ($/<star>.from) submatch

`$/.from`	the initial match position
`$/.to`	the final match position
`$/.chars`	`$/.to - $/.from`
`$/.orig`	the original match string
`$/.Str`	`substr($/.orig, $/.from, $/.chars)`
`$/.ast`	the abstract result associated with this node
`$/.caps`	sequential captures
`$/.chunks`	sequential tokenization
`$/.prematch`	`$/.orig.substr(0, $/.from)`
`$/.postmatch`	`$/.orig.substr($/.to)`

Flow Control

Closure Traits

aka phasers. Every block can contain special named blocks (some are only for loops) that are started at certain times. They are traits (compile time property) of a block object. Those marked with a * can also be used within an expression as in BEGIN my $x = 3 * 3;.

BEGIN {...}*	at compile time, ASAP, only ever runs once
CHECK {...}*	at compile time, ALAP, only ever runs once

INIT {...}*	at run time, ASAP, only ever runs once
END {...}	at run time, ALAP, only ever runs once

ENTER {...}*	at every block entry time, repeats on loop blocks.
LEAVE {...}	at every block exit time
KEEP {...}	at every successful block exit, part of LEAVE queue
UNDO {...}	at every unsuccessful block exit, part of LEAVE queue

FIRST {...}*	at loop initialization time, before any ENTER
NEXT {...}	at loop continuation time, before any LEAVE
LAST {...}	at loop termination time, after any LEAVE

PRE {...}	assert precondition at every block entry, before ENTER
POST {...}	assert postcondition at every block exit, after LEAVE

CATCH {...}	catch exceptions, before LEAVE
CONTROL {...}	catch control exceptions (like next/last/return etc), before LEAVE

Jump Commands

goto	jump to a named label
redo	repeat this loop turn
next	skip to the next loop turn
last	leave this loop now
[succeed](appendix-a-index#'succeed)	leave this when clause and surrounding given block
proceed	check next when clauses
leave	leave this block with a return value
return	leave this routine with a return value

Conditionals

if	when following expression evals in boolean context to True, the block that following after that will be executed
elsif	works like if, but only recognized if no preceding "if" or "elsif" clause was executed
else	following block will be executed, when no preceding "if" or "elsif" clause was executed
unless	opposite of if, alias to if not, no "elsif" or "else" is allowed to follow
?? !!	"cond ?? term1 !! term2" is short form "of if cond {term1} else {term2}"
ff	awk style flip flop, in P5 .. in scalar context
fff	sed style flip flop, in P5 ... in scalar context
given	evals an expression into scalar context assignes it to $_ for the following block
when	smartmatches an expression against `$_`; if the result is True, the following block will be executed
default	following block will be executed, when no "when" clause was executed

Loops

loop	general (endless) loop, unless used as an C-style-loop, evals following expression into void context
while	loop with negative exit condition (exit when False), condition, evals expression into boolean context
until	loop with positive exit condition(exit when True), evals expression into boolean context
repeat	initial command for while or until loops that have their condtion at the end
do	runs that block in any case one time, "do once"-loop
for	evals expression into lazy list context and iterates over that list from first to last value, sets each time `$_` (can be combined with when as well),

Routines

routine definition: [scope] [modifier] type [name] [trait] (signature) { block }

Routine Types

sub	normal routine, named block with parmeters
method	inheritable object methods
submethod	not inheritable methods
regex	routine that executes a regular expression
rule	alias to regex :ratchet :sigspace
token	alias to regex :ratchet
macro	routine that is compiled to an AST at BEGIN (ASAP, compile time)
quasi	block that is compiled to an AST at runtime

Routine Modifier

multi	marks routines, which can have siblings with same name but different signature; when called, the one with matching sig is executed
only	routines which don't allow siblings (this is default, you may leave it out)
proto	fallback for multi, if no multi signature matches the caller, a proto with same name is executed

Routine Traits

phasers (closure traits) can also be seen as routine traits.

export	this routine will be exported my the current module by default
will do	block of code executed when the subroutine is called. Normally declared implicitly, by providing a block after the subroutine's signature definition
signature	signature of a subroutine. Normally declared implicitly, by providing a parameter list and/or return type
as	inner type constraint that a routine imposes on its return value
of	official return type of the routine
cached	marks a subroutine as being memoized
rw	marks a subroutine as returning an lvalue
parsed	macro is parsed once, is hygienic, only parsed can be used
reparsed	macro parsed twice, not hygienic, later parsed can be used
tighter	specifies the precedence of an operator higher than an existing operator as seen here
looser	specifies the precedence of an operator lower than an existing operator as seen here
equiv	specifies the precedence of an operator same as an existing operator as seen here
assoc	specifies the associativity of an operator explicitly as seen here

Parameter Traits

as	data coming through that parameter will be coerced to the type following as
readonly	immutable parameter
rw	mutable parameter (rw stands for: read write)
copy	read-writable copy of the original argument ("pass-by-value")
dynamic	parameter is an "environmental" variable, a lexical in the dynamic scope
parcel	raw reference, will not be contextualized

Signature Symbols

In routine and block definitions can be also some character with special meaning

`!`	suffix of required parameter (default when named, not positional)
`*`	prefix of slurpy arrays
`-->`	prefix of return type
`->`	prefix of named readonly parameters for a block (pointy block syntax)
`:`	prefix of named parameter, positional when without
`::`	prefix of a variable type introduced in a signature
`<->`	prefix of named writeable parameters for a block (double pointy block syntax)
`?`	suffix of optional parameter (default when positional, not named)
`^`	prefix of metaclass methods, `$obj.^methods();` is shortcut for `$obj.HOW.methods($obj);`

Callframe Methods

A callframe object is generated at run-time for each call of a block of code. If a block of code includes a callframe() call, the value returned from that call is the callframe object corresponding to the block of code. To get the value of other blocks and routines higher in the call stack, use callframe with args, or caller, with or without args.

Once you have a callframe object, you can call the following methods on it:

args	capture of args passed for this callframe
callframe	callframe call which navigates relative to self
caller	caller call which navigates relative to self
file	source .file corresponding to callframe
hints	compiler symbols in effect during originally compilation
inline	did control structure create callframe (rather than user)
leave	leave (return from) a particular callframe
line	line number in source .file corresponding to callframe
my	access to callframe's lexicals (read only)
package

Perl 6 Tablets Appendix B - Thematically Grouped Index