class Int

Integer (arbitrary-precision)

class Int is Cool does Real { ... }

Int objects store integral numbers of arbitrary size. Ints are immutable.

There are two main syntax forms for Int literals

123         # Int in decimal notation
:16<BEEF>   # Int in radix notations

Both forms allow underscores between any two digits which can serve as visual separators, but don't carry any meaning:

5_00000     # five Lakhs
500_000     # five hundred thousand

Methods

routine chr

multi sub    chr(Int:D ) returns Str:D
multi method chr(Int:D:) returns Str:D

Returns a one-character string, by interpreting the integer as a Unicode codepoint number and converting it the corresponding character.

routine expmod

multi sub    expmod (Int:D: Int $y, Int $mod) returns Int:D
multi method expmod (Int:D: Int $y, Int $mod) returns Int:D

Returns the given Int raised to the $y power within modulus $mod.

routine is-prime

multi sub    is-prime (Int:D: Int $tries = 100) returns Bool:D
multi method is-prime (Int:D: Int $tries = 100) returns Bool:D

Returns True if this Int is known to be a prime, or is likely to be a prime based on a probabilistic Miller-Rabin test. $tries is the maximal number of iterations the test is allowed to do.

Returns False if this Int is known not to be a prime.

routine lsb

multi method lsb(Int:D:)
multi sub    lsb(Int:D)

Returns Nil if the number is 0. Otherwise returns the zero-based index from the right of the first 1 in the binary representation of the number.

say 0b01011.lsb;        # 0
say 0b01010.lsb;        # 1
say 0b10100.lsb;        # 2
say 0b01000.lsb;        # 3
say 0b10000.lsb;        # 4

routine msb

multi method msb(Int:D:)
multi sub    msb(Int:D)

Returns Nil if the number is 0. Otherwise returns the zero-based index from the left of the first 1 in the binary representation of the number.

say 0b00001.msb;        # 0
say 0b00011.msb;        # 1
say 0b00101.msb;        # 2
say 0b01010.msb;        # 3
say 0b10011.msb;        # 4

Operators

infix div

multi sub infix:<div>(Int:D, Int:D) returns Int:D

Does an integer division, rounded down.

Type graph

Below you should see a clickable image showing the type relations for Int that links to the documentation pages for the related types. If not, try the PNG version instead.

perl6-type-graph Int Int Cool Cool Int->Cool Real Real Int->Real Mu Mu Any Any Any->Mu Cool->Any Numeric Numeric Real->Numeric int int int->Int PromiseStatus PromiseStatus PromiseStatus->Int Signal Signal Signal->Int

Routines supplied by role Real

Int does role Real, which provides the following methods:

method Rat

method Rat(Real:D: Real $epsilon = 1e-6)

Converts the number to a Rat with the precision $epsilon.

routine rand

sub term:<rand> returns Num:D
method rand(Real:D:) returns Real:D

Returns a pseudo-random number between zero and the number.

The term form returns a pseudo-random Num between 0e0 and 1e0.

method sign

method sign(Real:D:)

Returns -1 if the number is negative, 0 if it is zero and 1 otherwise.

method round

method round(Real:D: $scale = 1)

Rounds the number to scale $scale. If $scale is 1, rounds to an integer. If scale is 0.1, rounds to one digit after the comma etc.

method floor

method floor(Real:D) returns Int:D

Return the largest integer not greater than the number.

method ceiling

method ceiling(Real:D) returns Int:D

Returns the smallest integer not less than the number.

method truncate

method truncate(Real:D) returns Int:D

Rounds the number towards zero.

method base

method base(Real:D: Int:D $base where 2..36, $digits?) returns Str:D

Converts the number to a string, using $base as base. For $base larger than ten, capital Latin letters are used.

255.base(16)            # 'FF'

The optional $digits argument asks for that many digits of fraction (which may not be negative). If omitted, a reasonable default is chosen based on type. For Int this default is 0. For Num, the default is 8. For Rational, the number of places is scaled to the size of the denominator, with a minimum of 6.

The final digit produced is always rounded.

say pi.base(10, 5);     # 3.14159

Routines supplied by role Numeric

Int does role Numeric, which provides the following methods:

method Real

method Real(Numeric:D:) returns Real:D

If this Numeric is equivalent to a Real, return that Real. Fail with X::Numeric::Real otherwise.

method Int

method Int(Numeric:D:) returns Int:D

If this Numeric is equivalent to a Real, return the equivalent of calling truncate on that Real to get an Int. Fail with X::Numeric::Real otherwise.

method Rat

method Rat(Numeric:D: Real $epsilon = 1.0e-6) returns Rat:D

If this Numeric is equivalent to a Real, return a Rat which is within $epsilon of that Real's value. Fail with X::Numeric::Real otherwise.

method Num

method Num(Numeric:D:) returns Num:D

If this Numeric is equivalent to a Real, return that Real as a Num as accurately as is possible. Fail with X::Numeric::Real otherwise.

method narrow

method narrow(Numeric:D) returns Numeric:D

Returns the number converted to the narrowest type that can hold it without loss of precision.

say (4.0 + 0i).narrow.perl;     # 4
say (4.0 + 0i).narrow.^name;    # Int

method ACCEPTS

multi method ACCEPTS(Numeric:D: $other)

Returns True if $other is numerically the same as the invocant.

routine log

multi sub    log(Numeric:D, Numeric $base = e) returns Numeric:D
multi method log(Numeric:D: Numeric $base = e) returns Numeric:D

Calculates the logarithm to base $base. Defaults to the natural logarithm.

routine log10

multi sub    log10(Numeric:D ) returns Numeric:D
multi method log10(Numeric:D:) returns Numeric:D

Calculates the logarithm to base 10.

routine exp

multi sub    exp(Numeric:D, Numeric:D $base = e) returns Numeric:D
multi method exp(Numeric:D: Numeric:D $base = e) returns Numeric:D

Returns $base to the power of the number, or e to the power of the number if called without a second argument.

method roots

multi method roots(Numeric:D: Int:D $n) returns Positional

Returns a list of the $n complex roots, which evaluate to the original number when raised to the $nth power.

routine abs

multi sub    abs(Numeric:D ) returns Real:D
multi method abs(Numeric:D:) returns Real:D

Returns the absolute value of the number.

routine sqrt

multi sub    sqrt(Numeric:D) returns Numeric:D
multi method sqrt(Numeric:D) returns Numeric:D

Returns a square root of the number. For real numbers the positive square root is returned.

On negative real numbers, sqrt returns NaN rather than a complex number, in order to not confuse people who are not familiar with complex arithmetic. If you want to calculate complex square roots, coerce to Complex first, or use the roots method.

method conj

multi method conj(Numeric:D) returns Numeric:D

Returns the complex conjugate of the number. Returns the number itself for real numbers.

method Bool

multi method Bool(Numeric:D:)

Returns False if the number is equivalent to zero, and True otherwise.

method succ

method succ(Numerid:D:)

Returns the number incremented by one (successor).

method pred

method pred(Numerid:D:)

Returns the number decremented by one (predecessor).

Routines supplied by class Cool

Int inherits from class Cool, which provides the following methods:

routine abs

method abs()
sub abs(Numeric() $x)

Coerces the invocant (or in the sub form, the argument) to Numeric and returns the absolute value (that is, a non-negative number).

say (-2).abs;       # 2
say abs "6+8i";     # 10

method conj

method conj()

Coerces the invocant to Numeric and returns the complex conjugate (that is, the number with the sign of the imaginary part negated).

say (1+2i).conj;        # 1-2i

routine sqrt

method sqrt()
sub sqrt(Numeric(Cool) $x)

Coerces the invocant to Numeric (or in the sub form, the arguemnt) and returns the square root, that is, a non-negative number that, when multiplied with itself, produces the original number.

say 4.sqrt;             # 2
say sqrt(2);            # 1.4142135623731

method sign

method sign()

Coerces the invocant to Numeric and returns its sign, that is, 0 if the number is 0, 1 for positive and -1 for negative values.

say 6.sign;             # 1
say (-6).sign;          # -1
say "0".sign;           # 0

method rand

method rand()

Coerces the invocant to Num and returns a pseudo-random value between zero and the number.

say 1e5.rand;           # 33128.495184283

routine sin

method sin()
sub sin(Numeric(Cool))

Coerces the invocant (or in the sub firm, the argument) to Numeric, interprets it as radians, returns its sine.

say sin(0);             # 0
say sin(pi/4);          # 0.707106781186547
say sin(pi/2);          # 1

Note that Perl 6 is no computer algebra system, so sin(pi) typically does not produce an exact 0, but rather a very small floating-point number.

routine asin

sub asin(Numeric(Cool))
method asin()

Coerces the invocant (or in the sub firm, the argument) to Numeric, and returns its arc-sine in radians.

say 0.1.asin;               # 0.10016742116156

routine cos

method cos()
sub cos(Numeric(Cool))

Coerces the invocant (or in sub form, the argument) to Numeric, interprets it as radians, returns its sine.

say 0.cos;                  # 1
say pi.cos;                 # -1
say cos(pi/2);              # 6.12323399573677e-17

routine acos

method acos()
sub acos(Numeric(Cool))

Coerces the invocant (or in sub form, the argument) to Numeric, and returns its arc-cosine in radians.

routine tan

method tan()
sub acos(Numeric(Cool))

Coerces the invocant (or in sub form, the argument) to Numeric, interprets it as radians, returns its tangens.

routine atan

method atan()
sub atan(Numeric(Cool))

Coerces the invocant (or in sub form, the argument) to Numeric, and returns its arc-tangens in radians.

routine atan2

method atan2($y = 1e0)
sub atan2(Numeric() $x, Numeric() $y = 1e0)

Coerces the arguments (including the invocant in the method form) to Numeric, and returns their two-argument arc-tangens in radians.

method sec

method sec()
sub sec(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, interprets it as radians, returns its secans, that is, the reciprocal of its cosine.

routine asec

method asec()
sub asec(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, and returns its arc-secans in radians.

routine cosec

method cosec()
sub cosec(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, interprets it as radians, returns its cosecans, that is, the reciprocal of its sine.

routine acosec

method acosec()
sub acosec(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, and returns its arc-cosecans in radians.

routine cotan

method cotan()
sub cotangens(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, interprets it as radians, returns its cotangens, that is, the reciprocal of its tangens.

routine acotan

method acotan()
sub acotan(Numeric(Cool))

Coerces the invocant (or in method form, its argument) to Numeric, and returns its arc-cotangens in radians.

routine sinh

method sinh()
sub sinh(Numeric(Cool))

Coerces the invocant (or in method form, its argument) to Numeric, and returns its Sine hyperbolicus.

routine asinh

method asinh()
sub asinh(Numeric(Cool))

Coerces the invocant (or in method form, its argument) to Numeric, and returns its Inverse Sine hyperbolicus.

routine cosh

method cosh()
sub cosh(Numeric(Cool))

Coerces the invocant (or in method form, its argument) to Numeric, and returns its Cosine hyperbolicus.

routine acosh

method acosh()
sub acosh(Numeric(Cool))

Coerces the invocant (or in method form, its argument) to Numeric, and returns its Inverse Cosine hyperbolicus.

routine tanh

method tanh()
sub tanh(Numeric(Cool))

Coerces the invocant (or in method form, its argument) to Numeric, and returns its Tangens hyperbolicus.

routine atanh

method atanh()
sub atanh(Numeric(Cool))

Coerces the invocant (or in method form, its argument) to Numeric, and returns its Inverse tangens hyperbolicus.

routine log

multi method log(Cool:D: Cool:D $base?)
multi sub log(Numeric(Cool) $number, Numeric(Cool) $base?)

Coerces the arguments (including the invocant in the method form) to Numeric, and returns its Logarithm to base $base, or to base e (Euler's Number) if no base was supplied (Natural logarithm.

say (e*e).log;                      # 2

routine log10

multi method log10()
multi sub log10(Cool(Numeric))

Coerces the invocant (or in the sub form, the invocant) to Numeric, and returns its Logarithm to base 10, that is, a number that approximatly produces the original number when raised to the power of 10.

say log10(1001);                    # 3.00043407747932

method exp

multi method exp(Cool:D: Cool:D $base?)
multi sub exp(Cool:D $pow, Cool:D $base?)

Coerces the arguments (including the invocant in the method from) to Numeric, and returns $base raised to the power of the first number. If no $base is supplied, e (Euler's Number) is used.

say 0.exp;      # 1
say 1.exp;      # 2.71828182845905
say 10.exp;     # 22026.4657948067

routine round

multi method round(Cool:D: $unit = 1)
multi sub round(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, and rounds it to the unit of $unit. If $unit is 1, rounds to the nearest integer.

say 1.7.round;          # 2
say 1.07.round(0.1);    # 1.1
say 21.round(10);       # 20

routine floor

multi method floor
multi sub floor(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, and rounds it downwards to the nearest integer.

say "1.99".floor;       # 1
say "-1.9".floor;       # -2
say 0.floor;            # 0

routine ceiling

multi method ceiling
multi sub ceiling(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, and rounds it upwards to the nearest integer.

say "1".ceiling;        # 1
say "-0.9".ceiling;     # 0
say "42.1".ceiling;     # 43

routine truncate

multi method truncate()
multi sub truncate(Numeric(Cool))

Coerces the invocant (or in sub form, its argument) to Numeric, and rounds it towards zero.

say 1.2.truncate        # 1
say truncate -1.2;      # -1

routine ord

method ord()
sub ord(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns the Unicode code point, number of the code point.

say 'a'.ord;            # 65

The inverse operation is chr.

Mnemonic: returns an ordinal number

routine chr

method chr()
sub chr(Int(Cool))

Coerces the invocant (or in sub form, its argument) to Int, interprets it as a Unicode code points, and returns a string made of that code point.

say '65'.chr;       # A

The inverse operation is ord.

Mnemonic: turns an integer into a character.

routine chars

method chars()
sub chars(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns the number of characters in the string. Characters should actually be grapheme clusters, though current implementation errornously count codepoints instead.

say 'møp'.chars;    # 3

routine codes

method codes()
sub codes(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns the number of Unicode code points.

say 'møp'.codes;    # 3

routine flip

method flip()
sub flip(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns a reversed version.

say 421.flip;       # 124

routine trim

method trim()
sub trim(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns the string with both leading and trailing whitespace stripped.

my $stripped = '  abc '.trim;
say "<$stripped>";          # <abc>

routine trim-leading

method trim-leading()
sub trim-leading(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns the string with leading whitespace stripped.

my $stripped = '  abc '.trim-leading;
say "<$stripped>";          # <abc >

routine trim-trailing

method trim-trailing()
sub trim-trailing(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns the string with both leading and trailing whitespace stripped.

my $stripped = '  abc '.trim-trailing;
say "<$stripped>";          # <  abc>

routine lc

method lc()
sub lc(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns it case-folded to lower case.

say "ABC".lc;       # abc

routine uc

method uc()
sub uc(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns it case-folded to upper case (capital letters).

say "Abc".uc;       # ABC

routine tc

method tc()
sub tc(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns it with the first letter case-folded to title case (or where not available, upper case).

say "abC".tc;       # AbC

routine tclc

method tclc()
sub tclc(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns it with the first letter case-folded to title case (or where not available, upper case), and the rest of the string case-folded to lower case..

say 'abC'.tclc;     # Abc

routine wordcase

method wordcase(:&filter = &tclc, Mu :$where = True)
sub wordcase(Str(Cool) $input, :&filter = &tclc, Mu :$where = True)

Coerces the invocant (or in sub form, the first argument) to Str, and filters each word that smart-matches against $where through the &filter. With the default filter (first character to upper case, rest to lower) and matcher (which accepts everything), this title-cases each word:

say "perl 6 programming".wordcase;      # Perl 6 Programming

With a mather:

say "have fun working on perl".wordcase(:where({ .chars > 3 }));
                                        # Have fun Working on Perl

With a customer filter too:

say "have fun working on perl".wordcase(:filter(&uc), :where({ .chars > 3 }));
                                        # HAVE fun WORKING on PERL

routine chop

method chop()
sub chop(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns it with the last character removed.

say 'perl'.chop;                        # per

routine chomp

method chomp()
sub chomp(Str(Cool))

Coerces the invocant (or in sub form, its argument) to Str, and returns it with the last character removed, if it is a logical newline.

say 'ab'.chomp.chars;                   # 2
say "a\n".chomp.chars;                  # 1

routine substr

method substr($from, $chars?)
sub substr(Str(Cool) $str, $from, $chars?)

Coerces the invocant (or in the sub form, the first argument) to Str, and returns the string starting from offset $from. If $chars is supplied, at most $chars characters are returned.

say 'zenith'.substr(2);         # nith
say 'zenith'.substr(0, 3);      # zen

# works on non-strings too:
say 20151224.substr(6);         # 24

# sub form:
say substr "zenith", 0, 3;      # zen

If the $from parameter is a Callable, it is called with the number of chars in the string as argument. This allows easy indexing relative to the end:

say 20151224.substr(*-2);       # 24

routine ords

method ords()
sub ords(Str(Cool) $str)

Coerces the invocant (or in the sub form, the first argument) to Str, and returns a list of Unicode codepoints for each character.

say "Perl 6".ords;              # 80 101 114 108 32 54
say ords 10;                    # 49 48

This is the list-returning version of ord. The inverse operation in chrs.

routine chrs

method chrs()
sub chrs(*@codepoints) return Str:D

Coerces the invocant (or in the sub form, the argument list) to a list of integers, and returns the string created by interpreting each integer as a Unicode codepoint, and joining the characters.

say <80 101 114 108 32 54>.chrs;    # Perl 6

This is the list-input version of chr. The inverse operation is ords.

routine split

multi method split(  Str:D $delimiter, $limit = Inf, :$all)
multi method split(Regex:D $delimiter, $limit = Inf, :$all)
multi sub    split(  Str:D $delimiter, Str(Cool) $input, $limit = Inf, :$all)
multi sub    split(Regex:D $delimiter, Str(Cool) $input, $limit = Inf, :$all)

Coerces the invocant (or in the sub form, the second argument) to Str, and splits it into pieces based on delimiters found in the string.

If $delimiter is a string, it is searched for literally and not treated as a regex.

If the named parameter :all is passed, the matches from $delimiter are included in the result list.

Note that unlike in Perl 5, empty chunks are not removed from the result list. If you want that behavior, consider using comb instead.

say split(';', "a;b;c").perl;          # ("a", "b", "c").list
say split(';', "a;b;c", :all).perl;    # ("a", ";", "b", ";", "c").list
say split(';', "a;b;c", 2).perl;       # ("a", "b;c").list
say split(';', "a;b;c", 2, :all).perl; #("a", ";", "b;c").list

say split(';', "a;b;c,d").perl;        # ("a", "b", "c,d").list
say split(/\;/, "a;b;c,d").perl;       # ("a", "b", "c,d").list
say split(/<[;,]>/, "a;b;c,d").perl;   # ("a", "b", "c", "d").list

routine lines

method lines()
sub lines(Str(Cool))

Coerces the invocant (and in sub form, the argument) to Str, decomposes it into lines (with the newline characters stripped), and returns the list of lines.

say lines("a\nb\n").join('|');          # a|b
say "some\nmore\nlines".lines.elems;    # 3

method words

method words(Int() $limit)

Coerces the invocant to Str, and returns a list of words that make up the string (and if $limit is supplied, only the first $limit words).

say 'The quick brown fox'.words.join('|');      # The|quick|brown|fox
say 'The quick brown fox'.words(2).join('|');   # The|quick

Only whitespace counts as word boundaries

say "isn't, can't".words.join('|');             # isn't,|can't

routine comb

multi method comb(Regex $matcher, $limit = *) returns List:D
multi sub comb(Regex $matcher, Str(Cool) $input, $limit = *) returns List:D

Returns all (or if supplied, at most $limit) matches of the invocant (method form) or the second argument (sub form) against the Regex as a list of strings.

say "6 or 12".comb(/\d+/).join(", ");           # 6, 12

routine index

multi sub    index(Str(Cool) $s, Str:D $needle, Int(Cool) $startpos = 0) returns Int
multi method index(Str(Cool) $needle, Int(Cool) $startpos = 0) returns Int

Coerces the first two arguments (in method form, also counting the invocant) to Str, and searches for $needle in the string starting from $startpos. It returns the offset into the string where $needle was found, and an undefined value if it was not found.

See the documentation in type Str for examples.

routine rindex

multi sub    rindex(Str(Cool) $haystack, Str(Cool) $needle, Int(Cool) $startpos = $haystack.chars)
multi method rindex(Str(Cool) $haystack: Str(Cool) $needle, Int(Cool) $startpos = $haystack.chars)

Coerces the first two arguments (including the invocant in method form) to Str and $startpos to Int, and returns the last position of $needle in $haystack not after $startpos. Returns an undefined value if $needle wasn't found.

See the documentation in type Str for examples.

routine roots

multi method roots(Int(Cool) $n)
multi sub roots(Numeric(Cool) $x, Int(Cool) $n)

Coerces the first argument (and in method form, the invocant) to Numeric and the second ($n) to Int, and produces a list of $n Complex $n-roots, which means numbers that, raised to the $nth power, approximately produce the original number.

For example

my $original = 16;
my @roots = $original.roots(4);
say @roots;

for @roots -> $r {
    say abs($r ** 4 - $original);
}

produces this output:

2+0i 1.22464679914735e-16+2i -2+2.44929359829471e-16i -3.67394039744206e-16-2i
1.77635683940025e-15
4.30267170434156e-15
8.03651692704705e-15
1.04441561648202e-14

method IO

method IO() returns IO::Path:D

Coerces the invocant to IO::Path.

.say for '.'.IO.dir;        # gives a directory listing

Routines supplied by class Any

Int inherits from class Any, which provides the following methods:

method ACCEPTS

multi method ACCEPTS(Any:D: Mu $other)

Returns True if $other === self (i.e. it checks object identity).

Many built-in types override this for more specific comparisons

method any

method any() returns Junction:D

Interprets the invocant as a list and creates an any-Junction from it.

say so 2 == <1 2 3>.any;        # True
say so 5 == <1 2 3>.any;        # False

method all

method all() returns Junction:D

Interprets the invocant as a list and creates an all-Junction from it.

say so 1 < <2 3 4>.all;         # True
say so 3 < <2 3 4>.all;         # False

method one

method one() returns Junction:D

Interprets the invocant as a list and creates an one-Junction from it.

say so 1 == (1, 2, 3).one;      # True
say so 1 == (1, 2, 1).one;      # False

method none

method none() returns Junction:D

Interprets the invocant as a list and creates an none-Junction from it.

say so 1 == (1, 2, 3).none;     # False
say so 4 == (1, 2, 3).none;     # True

method list

Interprets the invocant as a list, and returns that List.

say so 42.list.^name;           # List
say so 42.list.elems;           # 1

method flat

Interprets the invocant as a list, flattens it, and returns that list.

say ((1, 2), (3)).elems;        # 2
say ((1, 2), (3)).flat.elems;   # 3

method eager

Interprets the invocant as a list, evaluates it eagerly, and returns that list.

say (1..10).eager;              # 1 2 3 4 5 6 7 8 9 10

method elems

Interprets the invocant as a list, and returns the number of elements in the list.

say 42.elems;                   # 1
say <a b c>.elems;              # 3

method end

Interprets the invocant as a list, and returns the last index of that list.

say 6.end;                      # 0
say <a b c>.end;                # 2

method pairup

method pairup() returns List

Interprets the invocant as a list, and constructs a list of pairs from it, in the same way that assignment to a Hash does. That is, it takes two consecutive elements and constructs a pair from them, unless the item in the key position already is a pair (in which case the pair is passed is passed through, and the next list item, if any, is considered to be a key again).

say (a => 1, 'b', 'c').pairup.perl;     # ("a" => 1, "b" => "c").list

sub exit

sub exit(Int() $status = 0)

Exits the current process with return code $status.

Routines supplied by class Mu

Int inherits from class Mu, which provides the following methods:

routine defined

multi sub    defined(Mu) returns Bool:D
multi method defined()   returns Bool:D

Returns False on the type object, and True otherwise.

say Int.defined;                # False
say 42.defined;                 # True

Very few types (like Failure) override defined to return False even for instances:

sub fails() { fail 'oh noe' };
say fails().defined;            # False

routine Bool

multi sub    Bool(Mu) returns Bool:D
multi method Bool()   returns Bool:D

Returns False on the type object, and True otherwise.

Many built-in types override this to be False for empty collections, the empty string or numerical zeros

say Mu.Bool;                    # False
say Mu.new.Bool;                # True
say [1, 2, 3].Bool;             # True
say [].Bool;                    # False
say { 'hash' => 'full'}.Bool;   # True
say {}.Bool;                    # False

method Str

multi method Str()   returns Str

Returns a string representation of the invocant, intended to be machine readable. Method Str warns on type objects, and produces the empty string.

say Mu.Str;                     #!> use of uninitialized value of type Mu in string context

routine gist

multi sub    gist(Mu) returns Str
multi method gist()   returns Str

Returns a string representation of the invocant, optimized for fast recognition by humans.

The default gist method in Mu re-dispatches to the perl method for defined invocants, and returns the type name in parenthesis for type object invocants. Many built-in classes override the case of instances to something more specific.

gist is the method that say calls implicitly, so say $something and say $something.gist generally produce the same output.

say Mu.gist;        # (Mu)
say Mu.new.gist;    # Mu.new()

routine perl

multi sub    perl(Mu) returns Str
multi method perl()   returns Str

Returns a Perlish representation of the object (i.e., can usually be re-evaluated with EVAL to regenerate the object). The exact output of perl is implementation specific, since there are generally many ways to write a Perl expression that produces a particular value

method clone

method clone(*%twiddles)

Creates a shallow clone of the invocant. If named arguments are passed to it, their values are used in every place where an attribute name matches the name of a named argument.

class Point2D {
    has ($.x, $.y);
    multi method gist(Point2D:D:) {
        "Point($.x, $.y)";
    }
}

my $p = Point2D.new(x => 2, y => 3);

say $p;                     # Point(2, 3)
say $p.clone(y => -5);      # Point(2, -5)

method new

multi method new(*%attrinit)

Default method for constructing (create + initialize) new objects of a class. This method expects only named arguments which are then used to initialize attributes with accessors of the same name.

Classes may provide their own new method to override this default.

new triggers an object construction mechanism that calls submethods named BUILD in each class of an inheritance hierarchy, if they exist. See the documentation on object construction for more information.

method bless

method bless(*%attrinit) returns Mu:D

Lower-level object construction method than new.

Creates a new object of the same type as the invocant, uses the named arguments to initialize attributes, and returns the created object.

You can use this method when writing custom constructors:

class Point {
    has $.x;
    has $.y;
    multi method new($x, $y) {
        self.bless(:$x, :$y);
    }
}
my $p = Point.new(-1, 1);

(Though each time you write a custom constructor, remember that it makes subclassing harder).

method CREATE

method CREATE() returns Mu:D

Allocates a new object of the same type as the invocant, without initializing any attributes.

say Mu.CREATE.defined;  # True

method print

multi method print() returns Bool:D

Prints value to $*OUT after stringification using .Str method without adding a newline at end.

"abc\n".print;          # abc

method say

multi method say() returns Bool:D

Prints value to $*OUT after stringification using .gist method with newline at end.

say 42;                 # 42

method ACCEPTS

multi method ACCEPTS(Mu:U: $other)

ACCEPTS is the method that smart matching with the infix ~~ operator and given/when invokes on the right-hand side (the matcher).

The Mu:U multi performs a type check. Returns True if $other conforms to the invocant (which is always a type object or failure).

say 42 ~~ Mu;           # True
say 42 ~~ Int;          # True
say 42 ~~ Str;          # False

Note that there is no multi for defined invocants; this is to allow autothreading of junctions, which happens as a fallback mechanism when no direct candidate is available to dispatch to.

method WHICH

multi method WHICH() returns ObjAt:D

Returns an object of type ObjAt which uniquely identifies the object. Value types override this method which makes sure that two equivalent objects return the same return value from WHICH.

say 42.WHICH eq 42.WHICH;       # True

method WHERE

method WHERE() returns Int

Returns an Int representing the memory address of the object.

method WHY

multi method WHY()

Returns the attached Pod value. For instance,

    sub cast(Spell $s)
    #= Initiate a specified spell normally
    #= (do not use for class 7 spells)
    {
	do-raw-magic($s);
    }
    say &cast.WHY;

prints

Initiate a specified spell normally (do not use for class 7 spells)

See the documentation specification for details about attaching Pod to variables, classes, functions, methods, etc.

trait is export

multi sub trait_mod:<is>(Mu:U \type, :$export!)

Marks a type as being exported, that is, available to external users.

my class SomeClass is export { }

A user of a module or class automatically gets all the symbols imported that are marked as is export.

This documentation was generated from Int.pod.