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 

For your convenience common radix forms come with a prefix shortcut.

say so :2<11111111> == 0b11111111 == :8<377> == 0o377 == 255 == 0d255 == :16<ff> == 0xff;
# OUTPUT: «True␤» 

All 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 
0xBEEF_CAFE;   # a strange place 
:2<1010_1010># 0d170 

Radix notation also supports round and angle brackets which allow you to parse a string for a given base, and putting together digits into a whole number respectively:

:16("9F");         # 159 
:100[9923];    # 990203 

These notations allow you to use variables, too:

my $two = "2";
my $ninety-nine = "99";
:16($ninety-nine); # 153 
:100[99$two3]; # 990203 


method Capture

Defined as:

method Capture()

Throws X::Cannot::Capture.

routine chr

Defined as:

multi sub    chr(Int:D  --> Str:D)
multi method chr(Int:D: --> Str:D)

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


65.chr;  # returns "A" 
196.chr# returns "Ä" 

routine expmod

Defined as:

multi sub    expmod(      $x,     $y,     $mod --> Int:D)
multi sub    expmod(Int:D $xInt $yInt $mod --> Int:D)
multi method expmod(Int:D:    Int $yInt $mod --> Int:D)

Returns the given Int raised to the $y power within modulus $mod, that is gives the result of ($x ** $y) mod $mod. The subroutine form can accept non-Int arguments, which will be coerced to Int.

say expmod(425);    # OUTPUT: «1␤» 
say 7.expmod(25);     # OUTPUT: «4␤» 

method polymod

Defined as:

method polymod(Int:D: +@mods)

Returns a sequence of mod results corresponding to the divisors in @mods. The divisors are given from smallest "unit" to the largest (e.g. 60 seconds per minute, 60 minutes per hour) and the results are returned in the same way: from smallest to the largest (5 seconds, 4 minutes).

Returns one more item in the result than the number of given divisors. If the divisors are given as a lazy list, runs until the remainder is 0 or the list of divisors is exhausted. All divisors must be Ints, unless the method is called on a non-Int number.

my $seconds = 1 * 60*60*24 # days 
            + 3 * 60*60    # hours 
            + 4 * 60       # minutes 
            + 5;           # seconds 
say $seconds.polymod(6060);                # OUTPUT: «(5 4 27)␤» 
say $seconds.polymod(606024);            # OUTPUT: «(5 4 3 1)␤» 
say 120.polymod:      11010², 10³, 10⁴;  # OUTPUT: «(0 0 12 0 0 0)␤» 
say 120.polymod: lazy 11010², 10³, 10⁴;  # OUTPUT: «(0 0 12)␤» 
say 120.polymod:      11010² … ∞;        # OUTPUT: «(0 0 12)␤» 
say ⅔.polymod(⅓);                            # OUTPUT: «(0 2)␤» 
say 5.Rat.polymod(.3.2);                   # OUTPUT: «(0.2 0 80)␤» 
my @digits-in-base37 = 9123607.polymod(37 xx *); # Base conversion 
say @digits-in-base37.reverse                    # OUTPUT: «[4 32 4 15 36]␤» 

To illustrate how the Int, non-lazy version of polymod works, consider this code that implements it:

my $seconds = 2 * 60*60*24 # days 
            + 3 * 60*60    # hours 
            + 4 * 60       # minutes 
            + 5;           # seconds 
my @pieces;
for 606024 -> $divisor {
    @pieces.push: $seconds mod $divisor;
    $seconds div= $divisor
@pieces.push: $seconds;
say @pieces# OUTPUT: «[5 4 3 2]␤» 

For a more detailed discussion, see this blog post

routine is-prime

Defined as:

multi sub    is-prime (Int:D $number --> Bool:D)
multi method is-prime (Int:D: --> 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.

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

say;         # OUTPUT: «True␤» 
say is-prime(9);        # OUTPUT: «False␤» 

routine lsb

Defined as:

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 least significant (rightmost) 1 in the binary representation of the number.

say 0b01011.lsb;        # OUTPUT: «0␤» 
say 0b01010.lsb;        # OUTPUT: «1␤» 
say 0b10100.lsb;        # OUTPUT: «2␤» 
say 0b01000.lsb;        # OUTPUT: «3␤» 
say 0b10000.lsb;        # OUTPUT: «4␤» 

routine msb

Defined as:

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 right of the most significant (leftmost) 1 in the binary representation of the number.

say 0b00001.msb;        # OUTPUT: «0␤» 
say 0b00011.msb;        # OUTPUT: «1␤» 
say 0b00101.msb;        # OUTPUT: «2␤» 
say 0b01010.msb;        # OUTPUT: «3␤» 
say 0b10011.msb;        # OUTPUT: «4␤» 

routine unival

Defined as:

multi sub    unival(Int:D  --> Numeric)
multi method unival(Int:D: --> Numeric)

Returns the number represented by the Unicode codepoint with the given integer number, or NaN if it does not represent a number.

say ord("¾").unival;    # OUTPUT: «0.75␤» 
say 190.unival;         # OUTPUT: «0.75␤» 
say unival(65);         # OUTPUT: «NaN␤» 


infix div

multi sub infix:<div>(Int:DInt:D --> Int:D)

Does an integer division, rounded down.

Type Graph

Type relations for Int
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 PromiseStatus PromiseStatus PromiseStatus->Int atomicint atomicint atomicint->Int Bool Bool Bool->Int Stringy Stringy Str Str Str->Cool Str->Stringy IntStr IntStr IntStr->Int IntStr->Str Signal Signal Signal->Int Order Order Order->Int int int int->Int

Stand-alone image: vector

Routines supplied by role Real

Int does role Real, which provides the following methods:

(Real) method Bridge

Defined as:

method Bridge(Real:D:)

Default implementation coerces the invocant to Num and that's the behaviour of this method in core Real types. This method primarily exist to make it easy to implement custom Real types by users, with the Bridge method returning one of the core Real types (NOT necessarily a Num) that best represent the custom Real type. In turn, this lets all the core operators and methods obtain a usable value they can work with.

As an example, we can implement a custom Temperature type. It has a unit of measure and the value, which are given during instantiation. We can implement custom operators or conversion methods that work with this type. When it comes to regular mathematical operators, however, we can simply use the .Bridge method to convert the Temperature to Kelvin expressed in one of the core numeric types:

class Temperature is Real {
    has Str:D  $.unit  is required where any <K F C>;
    has Real:D $.value is required;
    method new ($value:$unit = 'K'{ self.bless :$value :$unit }
    # Note: implementing .new() that handles $value of type Temperature is left as an exercise 
    method Bridge {
        when $!unit eq 'F' { ($!value + 459.67) × 9/5 }
        when $!unit eq 'C' {  $!value + 273.15 }
    method gist { self.Str }
    method Str  { "$!value degrees $!unit" }
sub postfix:<> { $^value:unit<C> }
sub postfix:<> { $^value:unit<F> }
sub postfix:<K> { $^value:unit<K> }
my $human := 36.6℃;
my $book  := 451℉;
my $sun   := 5778K;
say $human;                # OUTPUT: «36.6 degrees C␤» 
say $human + $book + $sun# OUTPUT: «7726.956␤» 
say 123+ 456K;           # OUTPUT: «579␤» 

As we can see from the last two lines of the output, the type of the bridged result is not forced to be any particular core type. It is a Rat, when we instantiated Temperature with a Rat or when conversion was involved, and it is an Int when we instantiated Temperature with an Int.

(Real) method Rat

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

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

(Real) method Real

Defined as:

multi method Real(Real:D: --> Real:D)
multi method Real(Real:U: --> Real:D)

The :D variant simply returns the invocant. The :U variant issues a warning about using an uninitialized value in numeric context and then returns

(Real) routine rand

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

Returns a pseudo-random number between zero (inclusive) and the number (non-inclusive.)

The term form returns a pseudo-random Num between 0e0 (inclusive) and 1e0 (non-inclusive.)

(Real) method sign

method sign(Real:D:)

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

(Real) 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.

(Real) method floor

method floor(Real:D --> Int:D)

Return the largest integer not greater than the number.

(Real) method ceiling

method ceiling(Real:D --> Int:D)

Returns the smallest integer not less than the number.

(Real) method truncate

method truncate(Real:D --> Int:D)

Rounds the number towards zero.

(Real) method base

method base(Real:D: Int:D $base where 2..36$digits? --> 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.

A special value of Whatever (*) can be given as $digits, which functions the same as when $digits is not specified for all Real types except the Rationals. For Rationals, the Whatever indicates that you wish all of the possible digits of the fractional part, but use caution: since there's no detection of repeating fractional parts (the algorithm will eventually stop after generating 2**63 digits).

The final digit produced is always rounded.

say pi.base(103);      # OUTPUT: «3.142␤» 
say (1/128).base(10*); # OUTPUT: «0.0078125␤» 
say (1/100).base(10*); # OUTPUT: «0.01␤» 
say (1/3)  .base(10*); # WRONG: endlessly repeating fractional part 

For reverse operation, see parse-base

Routines supplied by role Numeric

Int does role Numeric, which provides the following methods:

(Numeric) method Numeric

Defined as:

multi method Numeric(Numeric:D: --> Numeric:D)
multi method Numeric(Numeric:U: --> Numeric:D)

The :D variant simply returns the invocant. The :U variant issues a warning about using an uninitialized value in numeric context and then returns

(Numeric) method Int

method Int(Numeric:D: --> 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.

(Numeric) method Rat

method Rat(Numeric:D: Real $epsilon = 1.0e-6 --> 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.

(Numeric) method Num

method Num(Numeric:D: --> 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.

(Numeric) method narrow

method narrow(Numeric:D --> Numeric:D)

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

say (4.0 + 0i).narrow.perl;     # OUTPUT: «4␤» 
say (4.0 + 0i).narrow.^name;    # OUTPUT: «Int␤» 

(Numeric) method ACCEPTS

multi method ACCEPTS(Numeric:D: $other)

Returns True if $other can be coerced to Numeric and is numerically equal to the invocant (or both evaluate to NaN).

(Numeric) routine log

multi sub    log(Numeric:DNumeric $base = e --> Numeric:D)
multi method log(Numeric:D: Numeric $base = e --> Numeric:D)

Calculates the logarithm to base $base. Defaults to the natural logarithm. Returns NaN if $base is negative. Throws an exception if $base is 1.

(Numeric) routine log10

multi sub    log10(Numeric:D  --> Numeric:D)
multi method log10(Numeric:D: --> Numeric:D)

Calculates the logarithm to base 10. Returns NaN for negative arguments and -Inf for 0.

(Numeric) routine exp

multi sub    exp(Numeric:DNumeric:D $base = e --> Numeric:D)
multi method exp(Numeric:D: Numeric:D $base = e --> Numeric:D)

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

(Numeric) method roots

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

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

(Numeric) routine abs

multi sub    abs(Numeric:D  --> Real:D)
multi method abs(Numeric:D: --> Real:D)

Returns the absolute value of the number.

(Numeric) routine sqrt

multi sub    sqrt(Numeric:D --> Numeric:D)
multi method sqrt(Numeric:D --> 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.

(Numeric) method conj

multi method conj(Numeric:D --> Numeric:D)

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

(Numeric) method Bool

multi method Bool(Numeric:D:)

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

(Numeric) method succ

method succ(Numeric:D:)

Returns the number incremented by one (successor).

(Numeric) method pred

method pred(Numeric:D:)

Returns the number decremented by one (predecessor).

Routines supplied by class Cool

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

(Cool) routine abs

Defined as:

sub abs(Numeric() $x)
method abs()

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;       # OUTPUT: «2␤» 
say abs "6+8i";     # OUTPUT: «10␤» 

(Cool) method conj

Defined as:

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;        # OUTPUT: «1-2i␤» 

(Cool) routine sqrt

Defined as:

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

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

say 4.sqrt;             # OUTPUT: «2␤» 
say sqrt(2);            # OUTPUT: «1.4142135623731␤» 

(Cool) method sign

Defined as:

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;             # OUTPUT: «1␤» 
say (-6).sign;          # OUTPUT: «-1␤» 
say "0".sign;           # OUTPUT: «0␤» 

(Cool) method rand

Defined as:

method rand()

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

say 1e5.rand;           # OUTPUT: «33128.495184283␤» 

(Cool) routine sin

Defined as:

sub sin(Numeric(Cool))
method sin()

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

say sin(0);             # OUTPUT: «0␤» 
say sin(pi/4);          # OUTPUT: «0.707106781186547␤» 
say sin(pi/2);          # OUTPUT: «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.

(Cool) routine asin

Defined as:

sub asin(Numeric(Cool))
method asin()

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

say 0.1.asin;               # OUTPUT: «0.10016742116156␤» 
say asin(0.1);              # OUTPUT: «0.10016742116156␤» 

(Cool) routine cos

Defined as:

sub cos(Numeric(Cool))
method cos()

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

say 0.cos;                  # OUTPUT: «1␤» 
say pi.cos;                 # OUTPUT: «-1␤» 
say cos(pi/2);              # OUTPUT: «6.12323399573677e-17␤» 

(Cool) routine acos

Defined as:

sub acos(Numeric(Cool))
method acos()

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

say 1.acos;                 # OUTPUT: «0␤» 
say acos(-1);               # OUTPUT: «3.14159265358979␤» 

(Cool) routine tan

Defined as:

sub tan(Numeric(Cool))
method tan()

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

say tan(3);                 # OUTPUT: «-0.142546543074278␤» 
say 3.tan;                  # OUTPUT: «-0.142546543074278␤» 

(Cool) routine atan

Defined as:

sub atan(Numeric(Cool))
method atan()

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

say atan(3);                # OUTPUT: «1.24904577239825␤» 
say 3.atan;                 # OUTPUT: «1.24904577239825␤» 

(Cool) routine atan2

Defined as:

sub atan2(Numeric() $xNumeric() $y = 1e0)
method atan2($y = 1e0)

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

say atan2(3);               # OUTPUT: «1.24904577239825␤» 
say 3.atan2;                # OUTPUT: «1.24904577239825␤» 

(Cool) method sec

Defined as:

sub sec(Numeric(Cool))
method sec()

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

say 45.sec;                 # OUTPUT: «1.90359440740442␤» 
say sec(45);                # OUTPUT: «1.90359440740442␤» 

(Cool) routine asec

Defined as:

sub asec(Numeric(Cool))
method asec()

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

say 1.asec;                 # OUTPUT: «0␤» 
say sqrt(2).asec;           # OUTPUT: «0.785398163397448␤» 

(Cool) routine cosec

Defined as:

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

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

say 0.45.cosec;             # OUTPUT: «2.29903273150897␤» 
say cosec(0.45);            # OUTPUT: «2.29903273150897␤» 

(Cool) routine acosec

Defined as:

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

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

say 45.acosec;              # OUTPUT: «0.0222240516182672␤» 
say acosec(45)              # OUTPUT: «0.0222240516182672␤» 

(Cool) routine cotan

Defined as:

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

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

say 45.cotan;               # OUTPUT: «0.617369623783555␤» 
say cotan(45);              # OUTPUT: «0.617369623783555␤» 

(Cool) routine acotan

Defined as:

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

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

say 45.acotan;              # OUTPUT: «0.0222185653267191␤» 
say acotan(45)              # OUTPUT: «0.0222185653267191␤» 

(Cool) routine sinh

Defined as:

sub sinh(Numeric(Cool))
method sinh()

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

say 1.sinh;                 # OUTPUT: «1.1752011936438␤» 
say sinh(1);                # OUTPUT: «1.1752011936438␤» 

(Cool) routine asinh

Defined as:

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

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

say 1.asinh;                # OUTPUT: «0.881373587019543␤» 
say asinh(1);               # OUTPUT: «0.881373587019543␤» 

(Cool) routine cosh

Defined as:

sub cosh(Numeric(Cool))
method cosh()

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

say cosh(0.5);              # OUTPUT: «1.12762596520638␤» 

(Cool) routine acosh

Defined as:

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

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

say acosh(45);              # OUTPUT: «4.4996861906715␤» 

(Cool) routine tanh

Defined as:

sub tanh(Numeric(Cool))
method tanh()

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

say tanh(0.5);              # OUTPUT: «0.46211715726001␤» 
say tanh(atanh(0.5));       # OUTPUT: «0.5␤» 

(Cool) routine atanh

Defined as:

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

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

say atanh(0.5);             # OUTPUT: «0.549306144334055␤» 

(Cool) routine sech

Defined as:

sub sech(Numeric(Cool))
method sech()

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

say 0.sech;                 # OUTPUT: «1␤» 

(Cool) routine asech

Defined as:

sub asech(Numeric(Cool))
method asech()

Coerces the invocant (or in sub form, its argument) to Numeric, and returns its Inverse hyperbolic secant.

say 0.8.asech;              # OUTPUT: «0.693147180559945␤» 

(Cool) routine cosech

Defined as:

sub cosech(Numeric(Cool))
method cosech()

Coerces the invocant (or in sub form, its argument) to Numeric, and returns its Hyperbolic cosecant.

say cosech(pi/2);           # OUTPUT: «0.434537208094696␤» 

(Cool) routine acosech

Defined as:

sub acosech(Numeric(Cool))
method acosech()

Coerces the invocant (or in sub form, its argument) to Numeric, and returns its Inverse hyperbolic cosecant.

say acosech(4.5);           # OUTPUT: «0.220432720979802␤» 

(Cool) routine cotanh

Defined as:

sub cotanh(Numeric(Cool))
method cotanh()

Coerces the invocant (or in sub form, its argument) to Numeric, and returns its Hyperbolic cotangent.

say cotanh(pi);             # OUTPUT: «1.00374187319732␤» 

(Cool) routine acotanh

Defined as:

sub acotanh(Numeric(Cool))
method acotanh()

Coerces the invocant (or in sub form, its argument) to Numeric, and returns its Inverse hyperbolic cotangent.

say acotanh(2.5);           # OUTPUT: «0.423648930193602␤» 

(Cool) routine cis

Defined as:

sub cis(Numeric(Cool))
method cis()

Coerces the invocant (or in sub form, its argument) to Numeric, and returns cos(argument) + i*sin(argument).

say cis(pi/4);              # OUTPUT: «0.707106781186548+0.707106781186547i␤» 

(Cool) routine log

Defined as:

multi sub log(Numeric(Cool$numberNumeric(Cool$base?)
multi method log(Cool:D: Cool:D $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). Returns NaN if $base is negative. Throws an exception if $base is 1.

say (e*e).log;              # OUTPUT: «2␤» 

(Cool) routine log10

Defined as:

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

Coerces the invocant (or in the sub form, the invocant) to Numeric, and returns its Logarithm to base 10, that is, a number that approximately produces the original number when raised to the power of 10. Returns NaN for negative arguments and -Inf for 0.

say log10(1001);            # OUTPUT: «3.00043407747932␤» 

(Cool) method exp

Defined as:

multi sub exp(Cool:D $powCool:D $base?)
multi method exp(Cool:D: 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;      # OUTPUT: «1␤» 
say 1.exp;      # OUTPUT: «2.71828182845905␤» 
say 10.exp;     # OUTPUT: «22026.4657948067␤» 

(Cool) method unpolar

Defined as:

method unpolar(Numeric(Cool))

Coerces the arguments (including the invocant in the method form) to Numeric, and returns a complex number from the given polar coordinates. The invocant (or the first argument in sub form) is the magnitude while the argument (i.e. the second argument in sub form) is the angle. The angle is assumed to be in radians.

say sqrt(2).unpolar(pi/4);      # OUTPUT: «1+1i␤» 

(Cool) routine round

Defined as:

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

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;          # OUTPUT: «2␤» 
say 1.07.round(0.1);    # OUTPUT: «1.1␤» 
say 21.round(10);       # OUTPUT: «20␤» 

Always rounds up if the number is at mid-point:

say (−.5 ).round;       # OUTPUT: «0␤» 
say ( .5 ).round;       # OUTPUT: «1␤» 
say (−.55).round(.1);   # OUTPUT: «-0.5␤» 
say ( .55).round(.1);   # OUTPUT: «0.6␤» 

(Cool) routine floor

Defined as:

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

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

say "1.99".floor;       # OUTPUT: «1␤» 
say "-1.9".floor;       # OUTPUT: «-2␤» 
say 0.floor;            # OUTPUT: «0␤» 

(Cool) routine ceiling

Defined as:

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

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

say "1".ceiling;        # OUTPUT: «1␤» 
say "-0.9".ceiling;     # OUTPUT: «0␤» 
say "42.1".ceiling;     # OUTPUT: «43␤» 

(Cool) routine truncate

Defined as:

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

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

say 1.2.truncate;       # OUTPUT: «1␤» 
say truncate -1.2;      # OUTPUT: «-1␤» 

(Cool) routine ord

Defined as:

sub ord(Str(Cool))
method ord()

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

say 'a'.ord;            # OUTPUT: «97␤» 

The inverse operation is chr.

Mnemonic: returns an ordinal number

(Cool) method path

Defined as:

method path()

DEPRECATED. Existed only in the Rakudo implementation and isn't part of any language released. Issues deprecation warnings in 6.d language and will be removed entirely when 6.e language is released.

Stringifies the invocant and converts it to IO::Path object. Use the .IO method instead.

(Cool) routine chr

Defined as:

sub chr(Int(Cool))
method chr()

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;       # OUTPUT: «A␤» 

The inverse operation is ord.

Mnemonic: turns an integer into a character.

(Cool) routine chars

Defined as:

sub chars(Str(Cool))
method chars()

Coerces the invocant (or in sub form, its argument) to Str, and returns the number of characters in the string. Please note that on the JVM, you currently get codepoints instead of graphemes.

say 'møp'.chars;    # OUTPUT: «3␤» 
say 'ã̷̠̬̊'.chars;      # OUTPUT: «1␤» 
say '👨‍👩‍👧‍👦🏿'.chars;      # OUTPUT: «1␤» 

Graphemes are user visible characters. That is, this is what the user thinks of as a “character”.

Graphemes can contain more than one codepoint. Typically the number of graphemes and codepoints differs when Prepend or Extend characters are involved (also known as Combining characters), but there are many other cases when this may happen. Another example is \c[ZWJ] (Zero-width joiner).

You can check Grapheme_Cluster_Break property of a character in order to see how it is going to behave:

say ã̷̠̬̊.uniprops(Grapheme_Cluster_Break); # OUTPUT: «(Other Extend Extend Extend Extend)␤» 
say 👨‍👩‍👧‍👦🏿.uniprops(Grapheme_Cluster_Break); # OUTPUT: «(E_Base_GAZ ZWJ E_Base_GAZ ZWJ E_Base_GAZ ZWJ E_Base_GAZ E_Modifier)␤» 

You can read more about graphemes in the Unicode Standard, which Perl 6 tightly follows.

(Cool) routine codes

Defined as:

sub codes(Str(Cool))
method codes()

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

say 'møp'.codes;    # OUTPUT: «3␤» 

The same result will be obtained with

say +'møp'.ords;    # OUTPUT: «3␤» 

ords first obtains the actual codepoints, so there might be a difference in speed.

(Cool) routine flip

Defined as:

sub flip(Str(Cool))
method flip()

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

say 421.flip;       # OUTPUT: «124␤» 

(Cool) routine trim

Defined as:

sub trim(Str(Cool))
method trim()

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>";          # OUTPUT: «<abc>␤» 

(Cool) routine trim-leading

Defined as:

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

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>";          # OUTPUT: «<abc >␤» 

(Cool) routine trim-trailing

Defined as:

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

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

my $stripped = '  abc '.trim-trailing;
say "<$stripped>";          # OUTPUT: «<  abc>␤» 

(Cool) routine lc

Defined as:

sub lc(Str(Cool))
method lc()

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

say "ABC".lc;       # OUTPUT: «abc␤» 

(Cool) routine uc

Defined as:

sub uc(Str(Cool))
method uc()

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

say "Abc".uc;       # OUTPUT: «ABC␤» 

(Cool) routine fc

Defined as:

sub fc(Str(Cool))
method fc()

Coerces the invocant (or in sub form, its argument) to Str, and returns the result a Unicode "case fold" operation suitable for doing caseless string comparisons. (In general, the returned string is unlikely to be useful for any purpose other than comparison.)

say "groß".fc;       # OUTPUT: «gross␤» 

(Cool) routine tc

Defined as:

sub tc(Str(Cool))
method tc()

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;       # OUTPUT: «AbC␤» 

(Cool) routine tclc

Defined as:

sub tclc(Str(Cool))
method tclc()

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;     # OUTPUT: «Abc␤» 

(Cool) routine wordcase

Defined as:

sub wordcase(Str(Cool$input:&filter = &tclcMu :$where = True)
method wordcase(:&filter = &tclcMu :$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;      # OUTPUT: «Perl 6 Programming␤» 

With a matcher:

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 

(Cool) routine samecase

Defined as:

sub samecase(Cool $stringCool $pattern)
method samecase(Cool:D: Cool $pattern)

Coerces the invocant (or in sub form, the first argument) to Str, and returns a copy of $string with case information for each individual character changed according to $pattern. (The pattern string can contain three types of characters, i.e. uppercase, lowercase and caseless. For a given character in $pattern its case information determines the case of the corresponding character in the result.) If $string is longer than $pattern, the case information from the last character of $pattern is applied to the remaining characters of $string.

say "perL 6".samecase("A__a__"); # OUTPUT: «Perl 6␤» 
say "pERL 6".samecase("Ab");     # OUTPUT: «Perl 6␤» 

(Cool) method uniprop

Defined as:

multi sub uniprop(Str(Cool), |c)
multi sub uniprop(Int:D $codeStringy:D $propname)
multi sub uniprop(Str$codeStringy:D $propname)
multi method uniprop(|c)

Interprets the invocant as a Str, and returns the unicode property of the first character. If no property is specified returns the General Category. Returns a Bool for Boolean properties.

say 'a'.uniprop;               # OUTPUT: «Ll␤» 
say '1'.uniprop;               # OUTPUT: «Nd␤» 
say 'a'.uniprop('Alphabetic'); # OUTPUT: «True␤» 
say '1'.uniprop('Alphabetic'); # OUTPUT: «False␤» 

(Cool) method uniprops

Defined as:

sub uniprops(Str:D $strStringy:D $propname = "General_Category")

Interprets the invocant as a Str, and returns the unicode property for each character as a Seq. If no property is specified returns the General Category. Returns a Bool for Boolean properties. Similar to uniprop

(Cool) method uniname

Defined as:

sub uniname(Str(Cool--> Str)
method uniname(--> Str)

Interprets the invocant / first argument as a Str, and returns the Unicode codepoint name of the first codepoint of the first character. See uninames for a routine that works with multiple codepoints, and uniparse for the opposite direction.

# Camelia in Unicode 
say »ö«.uniname;
say "Ḍ̇".uniname# Note, doesn't show "COMBINING DOT ABOVE" 
# Find the char with the longest Unicode name. 
say (0..0x1FFFF).sort(*.uniname.chars)[*-1].chr.uniname;

(Cool) method uninames

Defined as:

sub uninames(Str:D)
method uninames()

Returns of a Seq of Unicode names for the all the codepoints in the Str provided.

say »ö«.uninames.perl;

Note this example, which gets a Seq where each element is a Seq of all the codepoints in that character.

say "Ḍ̇'oh".comb>>.uninames.perl;

See uniparse for the opposite direction.

(Cool) method unimatch

Defined as:

multi sub unimatch(Str:D $str|c)
multi unimatch(Int:D $codeStringy:D $pvalnameStringy:D $propname = $pvalname)

Checks if the given integer codepoint or the first letter of the string given have a unicode property equal to the value you give. If you supply the Unicode property to be checked it will only return True if that property matches the given value.

say unimatch 'A''Latin';           # OUTPUT: «True␤» 
say unimatch 'A''Latin''Script'# OUTPUT: «True␤» 
say unimatch 'A''Ll';              # OUTPUT: «True␤» 

(Cool) routine chop

Defined as:

sub chop(Str(Cool))
method chop()

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

say 'perl'.chop;                        # OUTPUT: «per␤» 

(Cool) routine chomp

Defined as:

sub chomp(Str(Cool))
method chomp()

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;                   # OUTPUT: «2␤» 
say "a\n".chomp.chars;                  # OUTPUT: «1␤» 

(Cool) routine substr

Defined as:

sub substr(Str(Cool$str$from$chars?)
method substr($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);         # OUTPUT: «nith␤» 
say 'zenith'.substr(03);      # OUTPUT: «zen␤» 
# works on non-strings too: 
say 20151224.substr(6);         # OUTPUT: «24␤» 
# sub form: 
say substr "zenith"03;      # OUTPUT: «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);       # OUTPUT: «24␤» 

(Cool) routine ords

Defined as:

sub ords(Str(Cool$str)
method ords()

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

say "Camelia".ords;              # OUTPUT: «67 97 109 101 108 105 97␤» 
say ords 10;                     # OUTPUT: «49 48␤» 

This is the list-returning version of ord. The inverse operation in chrs. If you are only interested in the number of codepoints, codes is a possibly faster option.

(Cool) routine chrs

Defined as:

sub chrs(*@codepoints --> Str:D)
method chrs()

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 <67 97 109 101 108 105 97>.chrs;   # OUTPUT: «Camelia␤» 

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

(Cool) routine split

Defined as:

multi sub    split(  Str:D $delimiterStr(Cool$input$limit = Inf:$k:$v:$kv:$p:$skip-empty)
multi sub    split(Regex:D $delimiterStr(Cool$input$limit = Inf:$k:$v:$kv:$p:$skip-empty)
multi sub    split(@delimitersStr(Cool$input$limit = Inf:$k:$v:$kv:$p:$skip-empty)
multi method split(  Str:D $delimiter$limit = Inf:$k:$v:$kv:$p:$skip-empty)
multi method split(Regex:D $delimiter$limit = Inf:$k:$v:$kv:$p:$skip-empty)
multi method split(@delimiters$limit = Inf:$k:$v:$kv:$p:$skip-empty)

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. You can also provide multiple delimiters by specifying them as a list; mixing Cool and Regex objects is OK.

say split(';'"a;b;c").perl;               # OUTPUT: «("a", "b", "c")␤» 
say split(';'"a;b;c"2).perl;            # OUTPUT: «("a", "b;c").Seq␤» 
say split(';'"a;b;c,d").perl;             # OUTPUT: «("a", "b", "c,d")␤» 
say split(/\;/"a;b;c,d").perl;            # OUTPUT: «("a", "b", "c,d")␤» 
say split(/<[;,]>/"a;b;c,d").perl;        # OUTPUT: «("a", "b", "c", "d")␤» 
say split(['a', /b+/4], '1a2bb345').perl# OUTPUT: «("1", "2", "3", "5")␤» 

By default, split omits the matches, and returns a list of only those parts of the string that did not match. Specifying one of the :k, :v, :kv, :p adverbs changes that. Think of the matches as a list that is interleaved with the non-matching parts.

The :v interleaves the values of that list, which will be either Match objects, if a Regex was used as a matcher in the split, or Str objects, if a Cool was used as matcher. If multiple delimiters are specified, Match objects will be generated for all of them, unless all of the delimiters are Cool.

say 'abc'.split(/b/:v);               # OUTPUT: «(a 「b」 c)␤» 
say 'abc'.split('b':v);               # OUTPUT: «(a b c)␤» 

:k interleaves the keys, that is, the indexes:

say 'abc'.split(/b/:k);               # OUTPUT: «(a 0 c)␤» 

:kv adds both indexes and matches:

say 'abc'.split(/b/:kv);               # OUTPUT: «(a 0 「b」 c)␤» 

and :p adds them as Pairs, using the same types for values as :v does:

say 'abc'.split(/b/:p);               # OUTPUT: «(a 0 => 「b」 c)␤» 
say 'abc'.split('b':p);               # OUTPUT: «(a 0 => b c)␤» 

You can only use one of the :k, :v, :kv, :p adverbs in a single call to split.

Note that empty chunks are not removed from the result list. For that behavior, use the `:skip-empty` named argument:

say ("f,,b,c,d".split: /","/             ).perl;  # OUTPUT: «("f", "", "b", "c", "d")␤» 
say ("f,,b,c,d".split: /","/:skip-empty).perl;  # OUTPUT: «("f", "b", "c", "d")␤» 

See also: comb.

(Cool) routine lines

Defined as:

sub lines(Str(Cool))
method lines()

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('|');          # OUTPUT: «a|b␤» 
say "some\nmore\nlines".lines.elems;    # OUTPUT: «3␤» 

This method can be used as part of an IO::Path to process a file line-by-line, since IO::Path objects inherit from Cool, e.g.:

for 'huge-csv'.IO.lines -> $line {
    # Do something with $line 
# or if you'll be processing later 
my @lines = 'huge-csv'.IO.lines;

Without any arguments, sub lines operates on $*ARGFILES, which defaults to $*IN in the absence of any filenames.

To modify values in place use is copy to force a writable container.

for $*IN.lines -> $_ is copy { s/(\w+)/{$0 ~ $0}/.say }

(Cool) method words

Defined as:

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('|');      # OUTPUT: «The|quick|brown|fox␤» 
say 'The quick brown fox'.words(2).join('|');   # OUTPUT: «The|quick␤» 

Only whitespace counts as word boundaries

say "isn't, can't".words.join('|');             # OUTPUT: «isn't,|can't␤» 

(Cool) routine comb

Defined as:

multi sub comb(Regex $matcherStr(Cool$input$limit = * --> Seq)
multi method comb(Regex $matcher$limit = * --> Seq)

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("");           # OUTPUT: «6, 12␤» 

(Cool) method contains

multi method contains(Cool:D: Str(Cool$needleCool $start? --> Bool:D)

Coerces the invocant and first argument to Str, and searches for $needle in the string starting from $start. Returns True if $needle is found.

say "Hello, World".contains('Hello');      # OUTPUT: «True␤» 
say "Hello, World".contains('hello');      # OUTPUT: «False␤» 
say "Hello, World".contains(',');          # OUTPUT: «True␤» 
say "Hello, World".contains(','3);       # OUTPUT: «True␤» 
say "Hello, World".contains(','10);      # OUTPUT: «False␤» 

Note that because of how a List or Array is coerced into a Str, the results may sometimes be surprising. See traps.

(Cool) routine index

Defined as:

multi sub    index(Str(Cool$sStr:D $needleInt(Cool$startpos = 0 --> Int)
multi method index(Str(Cool$needleInt(Cool$startpos = 0 --> 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.

(Cool) routine rindex

Defined as:

multi sub    rindex(Str(Cool$haystackStr(Cool$needleInt(Cool$startpos = $haystack.chars)
multi method rindex(Str(Cool$haystack: Str(Cool$needleInt(Cool$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.

(Cool) routine match

Defined as:

multi method match(Cool:D: $target*%adverbs)

Coerces the invocant to Str and calls the method match on it.

(Cool) method fmt

Defined as:

method fmt($format = '%s' --> Str:D)

Uses $format to return a formatted representation of the invocant.

For more information about formats strings, see sprintf.

say 11.fmt('This Int equals %03d');               # OUTPUT: «This Int equals 011␤» 
say '16'.fmt('Hexadecimal %x');                   # OUTPUT: «Hexadecimal 10␤» 

(Cool) routine roots

Defined as:

multi sub roots(Numeric(Cool$xInt(Cool$n)
multi method roots(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);
# OUTPUT:«2+0i 1.22464679914735e-16+2i -2+2.44929359829471e-16i -3.67394039744206e-16-2i␤» 
# OUTPUT:«1.77635683940025e-15␤» 
# OUTPUT:«4.30267170434156e-15␤» 
# OUTPUT:«8.03651692704705e-15␤» 
# OUTPUT:«1.04441561648202e-14␤» 

(Cool) method IO

Defined as:

method IO(--> IO::Path:D)

Coerces the invocant to IO::Path.

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

(Cool) routine EVAL

Defined as:

method EVAL(*%_)
sub EVAL($code where Cool|Blob:$lang = 'perl6')

Method form calls subroutine form with invocant as $code, passing along named args, if any. Subroutine form coerces Cool $code to Str. If $code is a Blob, it'll be processed using the same encoding as the $lang compiler would: for perl6, uses the encoding specified via --encoding command line argument, or utf-8 if none were given; for Perl5, processes using same rules as perl.

This works as-is with a literal string parameter. More complex input, such as a variable or string with embedded code, is illegal by default. This can be overridden in any of several ways:

use MONKEY;  # shortcut that turns on all MONKEY pragmas 
use Test;
# any of the above allows: 
EVAL "say { 5 + 5 }";   # OUTPUT: «10␤» 

Symbols in the current lexical scope are visible to code in an EVAL.

my $answer = 42;
EVAL 'say $answer;';    # OUTPUT: «42␤» 

However, since the set of symbols in a lexical scope is immutable after compile time, an EVAL can never introduce symbols into the surrounding scope.

EVAL 'my $lives = 9'say $lives;   # error, $lives not declared 

Furthermore, the EVAL is evaluated in the current package:

module M {
    EVAL 'our $answer = 42'
say $M::answer;         # OUTPUT: «42␤» 

And also the current language, meaning any added syntax is available:

sub infix:<mean>(*@ais assoc<list> {
    @a.sum / @a.elems
EVAL 'say 2 mean 6 mean 4';     # OUTPUT: «4␤» 

An EVAL statement evaluates to the result of the last statement:

sub infix:<mean>(*@ais assoc<list> {
    @a.sum / @a.elems
say EVAL 'say 1; 2 mean 6 mean 4';         # OUTPUT: «1␤4␤» 

EVAL is also a gateway for executing code in other languages:

EVAL "use v5.20; say 'Hello from perl5!'":lang<Perl5>;

(Cool) routine EVALFILE

Defined as:

sub EVALFILE($filename where Blob|Cool:$lang = 'perl6')

Slurps the specified file and evaluates it. Behaves the same way as EVAL with regard to Blob decoding, scoping, and the $lang parameter. Evaluates to the value produced by the final statement in the file.

EVALFILE "foo.p6";

Routines supplied by class Any

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

(Any) method ACCEPTS

Defined as:

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

(Any) method any

Defined as:

method any(--> Junction:D)

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

say so 2 == <1 2 3>.any;        # OUTPUT: «True␤» 
say so 5 == <1 2 3>.any;        # OUTPUT: «False␤» 

(Any) method all

Defined as:

method all(--> Junction:D)

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

say so 1 < <2 3 4>.all;         # OUTPUT: «True␤» 
say so 3 < <2 3 4>.all;         # OUTPUT: «False␤» 

(Any) method one

Defined as:

method one(--> Junction:D)

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

say so 1 == (123).one;      # OUTPUT: «True␤» 
say so 1 == (121).one;      # OUTPUT: «False␤» 

(Any) method none

Defined as:

method none(--> Junction:D)

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

say so 1 == (123).none;     # OUTPUT: «False␤» 
say so 4 == (123).none;     # OUTPUT: «True␤» 

(Any) method list

Defined as:

multi method list(Any:U: -->List)
multi method list(Any:D \SELF: -->List)

Applies the infix , operator to the invocant and returns the resulting List:

say 42.list.^name;           # OUTPUT: «List␤» 
say 42.list.elems;           # OUTPUT: «1␤» 

(Any) method push

Defined as:

method push(|values --> Positional:D)

The method push is defined for undefined invocants and allows for autovivifying undefined to an empty Array, unless the undefined value implements Positional already. The argument provided will then be pushed into the newly created Array.

my %h;
say %h<a>;     # OUTPUT: «(Any)␤»      <-- Undefined 
%h<a>.push(1); # .push on Any 
say %h;        # OUTPUT: «{a => [1]}␤» <-- Note the Array 

(Any) routine reverse

Defined as:

multi sub    reverse(*@list  --> Seq:D)
multi method reverse(List:D: --> Seq:D)

Returns a Seq with the same elements in reverse order.

Note that reverse always refers to reversing elements of a list; to reverse the characters in a string, use flip.


say <hello world!>.reverse;     # OUTPUT: «(world! hello)␤» 
say reverse ^10;                # OUTPUT: «(9 8 7 6 5 4 3 2 1 0)␤» 

(Any) method sort

Defined as:

multi method sort()
multi method sort(&custom-routine-to-use)

Sorts iterables with cmp or given code object and returns a new Seq. Optionally, takes a Callable as a positional parameter, specifying how to sort.


say <b c a>.sort;                           # OUTPUT: «(a b c)␤» 
say 'bca'.comb.sort.join;                   # OUTPUT: «abc␤» 
say 'bca'.comb.sort({$^b cmp $^a}).join;    # OUTPUT: «cba␤» 
say '231'.comb.sort(&infix:«<=>»).join;     # OUTPUT: «123␤» 

(Any) method map

Defined as:

multi method map(\SELF: &block;; :$label:$item)

map will iterate over the invocant and apply the number of positional parameters of the code object from the invocant per call. The returned values of the code object will become elements of the returned Seq.

The :$label and :$item are useful only internally, since for loops get converted to maps. The :$label takes an existing Label to label the .map's loop with and :$item controls whether the iteration will occur over (SELF,) (if :$item is set) or SELF.

(Any) method deepmap

Defined as:

method deepmap(&block --> Listis nodal

deepmap will apply &block to each element and return a new List with the return values of &block, unless the element does the Iterable role. For those elements deepmap will descend recursively into the sublist.

say [[1,2,3],[[4,5],6,7]].deepmap(* + 1);
# OUTPUT: «[[2 3 4] [[5 6] 7 8]]␤» 

(Any) method duckmap

Defined as:

method duckmap(&blockis rw is nodal

duckmap will apply &block on each element and return a new list with defined return values of the block. For undefined return values, duckmap will try to descend into the element if that element implements Iterable.

<a b c d e f g>.duckmap(-> $_ where <c d e>.any { .uc }).say;
# OUTPUT: «(a b C D E f g)␤» 
(('d''e'), 'f').duckmap(-> $_ where <e f>.any { .uc }).say;
# OUTPUT: «((d E) F)␤» 

(Any) method nodemap

Defined as:

method nodemap(&block --> Listis nodal

nodemap will apply &block to each element and return a new List with the return values of &block. In contrast to deepmap it will not descend recursively into sublists if it finds elements which does the Iterable role.

say [[1,2,3], [[4,5],6,7], 7].nodemap(*+1);
# OUTPUT: «(4, 4, 8)␤» 
say [[23], [4, [56]]]».nodemap(*+1)
# OUTPUT: «((3 4) (5 3))␤» 

The examples above would have produced the exact same results if we had used map instead of nodemap. The difference between the two lies in the fact that map flattens out slips while nodemap doesn't.

say [[2,3], [[4,5],6,7], 7].nodemap({.elems == 1 ?? $_ !! slip});
# OUTPUT: «(() () 7)␤» 
say [[2,3], [[4,5],6,7], 7].map({.elems == 1 ?? $_ !! slip});
# OUTPUT: «(7)␤» 

(Any) method flat

Defined as:

method flat(--> Seq:Dis nodal

Interprets the invocant as a list, flattens non-containerized Iterables into a flat list, and returns that list. Keep in mind Map and Hash types are Iterable and so will be flattened into lists of pairs.

say ((12), (3), %(:42a));      # OUTPUT: «((1 2) 3 {a => 42})␤» 
say ((12), (3), %(:42a)).flat# OUTPUT: «(1 2 3 a => 42)␤» 

Note that Arrays containerize their elements by default, and so flat will not flatten them. You can use hyper method call to call .List method on all the inner Iterables and so de-containerize them, so that flat can flatten them:

say [[123], [(45), 67]]      .flat# OUTPUT: «([1 2 3] [(4 5) 6 7])␤» 
say [[123], [(45), 67]]».List.flat# OUTPUT: «(1 2 3 4 5 6 7)␤» 

For more fine-tuned options, see deepmap, duckmap, and signature destructuring

(Any) method eager

Defined as:

method eager(--> Seq:Dis nodal

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

my  $range = 1..5;
say $range;         # OUTPUT: «1..5␤» 
say $range.eager;   # OUTPUT: «(1 2 3 4 5)␤» 

(Any) method elems

Defined as:

method elems(--> Int:Dis nodal

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

say 42.elems;                   # OUTPUT: «1␤» 
say <a b c>.elems;              # OUTPUT: «3␤» 

(Any) method end

method end(--> Any:Dis nodal

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

say 6.end;                      # OUTPUT: «0␤» 
say <a b c>.end;                # OUTPUT: «2␤» 

(Any) method pairup

Defined as:

method pairup(--> Seq:Dis nodal

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 (=> 1'b''c').pairup.perl;     # OUTPUT: «(:a(1), :b("c")).Seq␤» 

(Any) sub exit

Defined as:

sub exit(Int() $status = 0)

Exits the current process with return code $status or zero if no value has been specified. The exit value ($status), when different from zero, has to be opportunely evaluated from the process that catches it (e.g., a shell).

exit does prevent the LEAVE phaser to be executed.

exit should be used as last resort only to signal the parent process about an exit code different from zero, and should not be used to terminate exceptionally a method or a sub: use exceptions instead.

It is worth noting that the only way to return an exit code different from zero from a Main function is by means of using exit.

(Any) sub item

Defined as:

proto sub item(|) is pure
multi item(\x)
multi item(|c)
multi item(Mu $a)

Forces given object to be evaluated in item context and returns the value of it.

say item([1,2,3]).perl;              # OUTPUT: «$[1, 2, 3]␤» 
say item( %apple => 10 ) ).perl;   # OUTPUT: «${:apple(10)}␤» 
say item("abc").perl;                # OUTPUT: «"abc"␤» 

You can also use $ as item contextualizer.

say $[1,2,3].perl;                   # OUTPUT: «$[1, 2, 3]␤» 
say $("abc").perl;                   # OUTPUT: «"abc"␤» 

(Any) method Array

Defined as:

method Array(--> Array:Dis nodal

Coerce the invocant to Array.

(Any) method List

Defined as:

method List(--> List:Dis nodal

Coerce the invocant to List, using the list method.

(Any) method Hash

Defined as:

proto method Hash(|) is nodal
multi method Hash--> Hash:D)

Coerce the invocant to Hash by invoking the method hash on it.

(Any) method hash

Defined as:

proto method hash(|) is nodal
multi method hash(Any:U: --> Hash:D)
multi method hash(Any:D: --> Hash:D)

Creates a new Hash, empty in the case the invocant is undefined, or coerces the invocant to an Hash in the case it is defined.

my $d# $d is Any 
say $d.hash# OUTPUT: {} 
$d.append: 'a''b';
say $d.hash# OUTPUT: {a => b} 

(Any) method Slip

Defined as:

method Slip(--> Slip:Dis nodal

Coerce the invocant to Slip.

(Any) method Map

Defined as:

method Map(--> Map:Dis nodal

Coerce the invocant to Map.

(Any) method Bag

Defined as:

method Bag(--> Bag:Dis nodal

Coerce the invocant to Bag, whereby Positionals are treated as lists of values.

(Any) method BagHash

Defined as:

method BagHash(--> BagHash:Dis nodal

Coerce the invocant to BagHash, whereby Positionals are treated as lists of values.

(Any) method Set

Defined as:

method Set(--> Set:Dis nodal

Coerce the invocant to Set, whereby Positionals are treated as lists of values.

(Any) method SetHash

Defined as:

method SetHash(--> SetHash:Dis nodal

Coerce the invocant to SetHash, whereby Positionals are treated as lists of values.

(Any) method Mix

Defined as:

method Mix(--> Mix:Dis nodal

Coerce the invocant to Mix, whereby Positionals are treated as lists of values.

(Any) method MixHash

Defined as:

method MixHash(--> MixHash:Dis nodal

Coerce the invocant to MixHash, whereby Positionals are treated as lists of values.

(Any) method Supply

Defined as:

method Supply(--> Supply:Dis nodal

Coerce the invocant first to a list by applying the invocant's .list method, and then to a Supply.

(Any) method min

Defined As:

multi method min(--> Any:D)
multi method min(&filter --> Any:D)

Coerces to Iterable and returns the numerically smallest element.

If a Callable positional argument is provided, each value is passed into the filter, and its return value is compared instead of the original value. The original value is still the one returned from min.

say (1,7,3).min();       # OUTPUT:«1␤» 
say (1,7,3).min({1/$_}); # OUTPUT:«7␤» 

(Any) method max

Defined As:

multi method max(--> Any:D)
multi method max(&filter --> Any:D)

Coerces to Iterable and returns the numerically largest element.

If a Callable positional argument is provided, each value is passed into the filter, and its return value is compared instead of the original value. The original value is still the one returned from max.

say (1,7,3).max();       # OUTPUT:«7␤» 
say (1,7,3).max({1/$_}); # OUTPUT:«1␤» 

(Any) method minmax

Defined As:

multi method minmax(--> Range:D)
multi method minmax(&filter --> Range:D)

Returns a Range from the smallest to the largest element.

If a Callable positional argument is provided, each value is passed into the filter, and its return value is compared instead of the original value. The original values are still used in the returned Range.

say (1,7,3).minmax();      # OUTPUT:«1..7␤» 
say (1,7,3).minmax({-$_}); # OUTPUT:«7..1␤» 

(Any) method minpairs

Defined As:

multi method minpairs(Any:D: --> Seq:D)

Calls .pairs and returns a Seq with all of the Pairs with minimum values, as judged by the cmp operator:

<a b c a b c>.minpairs.perl.put# OUTPUT: «(0 => "a", 3 => "a").Seq␤» 
%(:42a, :75b).minpairs.perl.put# OUTPUT: «(:a(42),).Seq␤» 

(Any) method maxpairs

Defined As:

multi method maxpairs(Any:D: --> Seq:D)

Calls .pairs and returns a Seq with all of the Pairs with maximum values, as judged by the cmp operator:

<a b c a b c>.maxpairs.perl.put# OUTPUT: «(2 => "c", 5 => "c").Seq␤» 
%(:42a, :75b).maxpairs.perl.put# OUTPUT: «(:b(75),).Seq␤» 

(Any) method keys

Defined As:

multi method keys(Any:U: --> List)
multi method keys(Any:D: --> List)

For defined Any returns its keys after calling list on it, otherwise calls list and returns it.

say Any.keys# OUTPUT: «()␤» 

(Any) method flatmap

Defined As:

method flatmap(Any:U: &code --> Seq)

Coerces the Any to a list by applying the .list method and uses List.flatmap on it.

say Any.flatmap({.reverse}); # OUTPUT: «((Any))␤» 

In the case of Any, Any.list returns a 1-item list, as is shown.

(Any) method roll

Defined As:

multi method roll(--> Any)
multi method roll($n --> Seq)

Coerces the invocant Any to a list by applying the .list method and uses List.roll on it.

say Any.roll;    # OUTPUT: «(Any)␤» 
say Any.roll(5); # OUTPUT: «((Any) (Any) (Any) (Any) (Any))␤» 

(Any) method pick

Defined As:

multi method pick(--> Any)
multi method pick($n --> Seq)

Coerces the Any to a list by applying the .list method and uses List.pick on it.

say Any.pick;    # OUTPUT: «(Any)␤» 
say Any.pick(5); # OUTPUT: «((Any))␤» 

(Any) method skip

Defined As:

multi method skip(--> Seq)
multi method skip($n --> Seq)

Creates a Seq from 1-item list's iterator and uses Seq.skip on it.

say Any.skip;      # OUTPUT: «()␤» 
say Any.skip(5);   # OUTPUT: «()␤» 
say Any.skip(-1);  # OUTPUT: «((Any))␤» 
say Any.skip(*-1); # OUTPUT: «((Any))␤» 

(Any) method prepend

Defined As:

multi method prepend(--> Array)
multi method prepend(@values --> Array)

Initializes Any variable as empty Array and calls Array.prepend on it.

my $a;
say $a.prepend# OUTPUT: «[]␤» 
say $a;         # OUTPUT: «[]␤» 
my $b;
say $b.prepend(1,2,3); # OUTPUT: «[1 2 3]␤» 

(Any) method unshift

Defined As:

multi method unshift(--> Array)
multi method unshift(@values --> Array)

Initializes Any variable as empty Array and calls Array.unshift on it.

my $a;
say $a.unshift# OUTPUT: «[]␤» 
say $a;         # OUTPUT: «[]␤» 
my $b;
say $b.unshift([1,2,3]); # OUTPUT: «[[1 2 3]]␤» 

(Any) method first

Defined As:

method first(Mu $matcher?:$k:$kv:$p:$end)

Treats the Any as a 1-item list and uses List.first on it.

say Any.first# OUTPUT: «(Any)␤» 

(Any) method unique

Defined As:

method unique(:&as:&with --> Seq:D)

Treats the Any as a 1-item list and uses List.unique on it.

say Any.unique# OUTPUT: «((Any))␤» 

(Any) method repeated

Defined As:

method repeated(:&as:&with --> Seq)

Treats the Any as a 1-item list and uses List.repeated on it.

say Any.repeated# OUTPUT: «()␤» 

(Any) method squish

Defined As:

method squish(:&as:&with --> Seq)

Treats the Any as a 1-item list and uses List.squish on it.

say Any.squish# OUTPUT: «((Any))␤» 

(Any) method permutations

Defined As:

method permutations(--> Seq)

Treats the Any as a 1-item list and uses List.permutations on it.

say Any.permutations# OUTPUT: «(((Any)))␤» 

(Any) method categorize

Defined As:

method categorize(&mapper --> Hash:D)

Treats the Any as a 1-item list and uses List.categorize on it.

say Any.categorize({ $_ }); # OUTPUT: «{(Any) => [(Any)]}␤» 

(Any) method classify

Defined As:

method classify(&mapper -->Hash:D)

Treats the Any as a 1-item list and uses List.classify on it.

say Any.classify({ $_ }); # OUTPUT: «{(Any) => [(Any)]}␤» 

(Any) method produce

(Any) method pairs

Defined As:

multi method pairs(Any:U:  -->List)
multi method pairs(Any:D:  -->List)

Returns an empty List if the invocant is undefined, otherwise converts the invocant to a List via the list method and calls List.pairs on it:

say Any.pairs# OUTPUT: «()␤» 
my $a;
say $a.pairs;  # OUTPUT: «()» 
$a =;
say $a.pairs;  # OUTPUT: «(0 =>» 

(Any) method antipairs

Defined As:

multi method antipairs(Any:U:  -->List)
multi method antipairs(Any:D:  -->List)

Applies the method List.antipairs to the invocant, if it is defined, after having invoked list on it. If the invocant is not defined, it returns an empty List:

my $a;
say $a.antipairs;      # OUTPUT: «()» 
$a =;
say $a.antipairs;      # OUTPUT: «( => 0)» 

(Any) method kv

Defined As:

multi method kv(Any:U:  -->List)
multi method kv(Any:D:  -->List)

Returns an empty List if the invocant is not defined, otherwise it does invoke list on the invocant and then returns the result of List.kv on the latter:

my $a;
say $a.kv;      # OUTPUT: «()» 
$a =;
say $a.kv;      # OUTPUT: «(0» 
say Any.kv;     # OUTPUT: «()␤» 

(Any) method toggle

Defined as:

method toggle(Any:D: *@conditions where .all ~~ Callable:DBool :$off  --> Seq:D)

Iterates over the invocant, producing a Seq, toggling whether the received values are propagated to the result on and off, depending on the results of calling Callables in @conditions:

say ^10 .toggle: * < 4* %% 2&is-prime# OUTPUT: «(0 1 2 3 6 7)␤» 
say ^10 .toggle: :off* > 4;              # OUTPUT: «(5 6 7 8 9)␤» 

Imagine a switch that's either on or off (True or False), and values are produced if it's on. By default, the initial state of that switch is in "on" position, unless :$off is set to a true value, in which case the initial state will be "off".

A Callable from the head of @conditions is taken (if any are available) and it becomes the current tester. Each value from the original sequence is tested by calling the tester Callable with that value. The state of our imaginary switch is set to the return value from the tester: if it's truthy, set switch to "on", otherwise set it to "off".

Whenever the switch is toggled (i.e. switched from "off" to "on" or from "on" to "off"), the current tester Callable is replaced by the next Callable in @conditions, if available, which will be used to test any further values. If no more tester Callables are available, the switch will remain in its current state until the end of iteration.

# our original sequence of elements: 
say list ^10# OUTPUT: «(0 1 2 3 4 5 6 7 8 9)␤» 
# toggled result: 
say ^10 .toggle: * < 4* %% 2&is-prime# OUTPUT: «(0 1 2 3 6 7)␤» 
# First tester Callable is `* < 4` and initial state of switch is "on". 
# As we iterate over our original sequence: 
# 0 => 0 < 4 === True  switch is on, value gets into result, switch is 
#                      toggled, so we keep using the same Callable: 
# 1 => 1 < 4 === True  same 
# 2 => 2 < 4 === True  same 
# 3 => 3 < 4 === True  same 
# 4 => 4 < 4 === False switch is now off, "4" does not make it into the 
#                      result. In addition, our switch got toggled, so 
#                      we're switching to the next tester Callable 
# 5 => 5 %% 2 === False  switch is still off, keep trying to find a value 
# 6 => 6 %% 2 === True   switch is now on, take "6" into result. The switch 
#                        toggled, so we'll use the next tester Callable 
# 7 => is-prime(7) === True  switch is still on, take value and keep going 
# 8 => is-prime(8) === False switch is now off, "8" does not make it into 
#                            the result. The switch got toggled, but we 
#                            don't have any more tester Callables, so it 
#                            will remain off for the rest of the sequence. 

Since the toggle of the switch's state loads the next tester Callable, setting :$off to a True value affects when first tester is discarded:

# our original sequence of elements: 
say <0 1 2># OUTPUT: «(0 1 2)␤» 
# toggled result: 
say <0 1 2>.toggle: * > 1# OUTPUT: «()␤» 
# First tester Callable is `* > 1` and initial state of switch is "on". 
# As we iterate over our original sequence: 
# 0 => 0 > 1 === False  switch is off, "0" does not make it into result. 
#                      In addition, switch got toggled, so we change the 
#                      tester Callable, and since we don't have any more 
#                      of them, the switch will remain "off" until the end 
# our original sequence of elements: 
say <0 1 2># OUTPUT: «(0 1 2)␤» 
# toggled result: 
say <0 1 2>.toggle: :off* > 1# OUTPUT: «(2)␤» 
# First tester Callable is `* > 1` and initial state of switch is "off". 
# As we iterate over our original sequence: 
# 0 => 0 > 1 === False  switch is off, "0" does not make it into result. 
#                       The switch did NOT get toggled this time, so we 
#                       keep using our current tester Callable 
# 1 => 1 > 1 === False  same 
# 2 => 2 > 1 === True   switch is on, "2" makes it into the result 

(Any) method tree

Defined As:

method tree(--> Any)

Returns the class if it's undefined or if it's not iterable, returns the result of applying the tree method to the elements if it's Iterable.

say Any.tree# OUTPUT: «Any␤» 

.tree has different prototypes for Iterable elements.

my @floors = ( 'A', ('B','C', ('E','F','G')));
say @floors.tree(1).flat.elems# OUTPUT: «6␤» 
say @floors.tree(2).flat.elems# OUTPUT: «2␤» 
say @floors.tree*.join("-"), *.join(""), *.join("|" )); # OUTPUT: «A-B—C—E|F|G␤» 

With a number, it iteratively applies tree to every element in the lower level; the first instance will apply .tree(0) to every element in the array, and likewise for the next example.

The second prototype applies the Whatever code passed as arguments to every level in turn; the first argument will go to level 1 and so on. tree can, thus, be a great way to process complex all levels of complex, multi-level, data structures.

(Any) method nl-out

Defined As:

method nl-out(--> Str)

Returns Str with the value of "\n". See for the details.

say OUTPUT: «␤␤» 

(Any) method invert

Defined As:

method invert(--> List)

Returns an empty List.

say Any.invert# OUTPUT: «()␤» 

(Any) method combinations

Defined As:

method combinations(--> Seq)

Treats the Any as a 1-item list and uses List.combinations on it.

say Any.combinations# OUTPUT: «(() ((Any)))␤» 

(Any) method iterator

Defined As:

method iterator(--> Iterator)

Coerces the Any to a list by applying the .list method and uses iterator on it.

my $it = Any.iterator;
say $it.pull-one# OUTPUT: «(Any)␤» 
say $it.pull-one# OUTPUT: «IterationEnd␤» 

(Any) method grep

Defined As:

method grep(Mu $matcher:$k:$kv:$p:$v --> Seq)

Coerces the Any to a list by applying the .list method and uses List.grep on it.

Based on $matcher value can be either ((Any)) or empty List.

my $a;
say $a.grep({ True }); # OUTPUT: «((Any))␤» 
say $a.grep({ $_ });   # OUTPUT: «()␤» 

(Any) method append

Defined As:

proto method append(|) is nodal {*}
multi method append(Any:U \SELF: |values --> Array)

In the case the instance is not a positional-thing, it instantiate it as a new Array, otherwise clone the current instance. After that, it appends the values passed as arguments to the array obtained calling Array.append on it.

my $a;
say $a.append# OUTPUT: «[]␤» 
my $b;
say $b.append((1,2,3)); # OUTPUT: «[1 2 3]␤» 

(Any) method values

Defined As:

method values(--> List)

Returns an empty List.

(Any) method collate

Defined As:

method collate(--> Seq)


(Any) method cache

Defined As:

method cache(--> List)

Provides a List representation of the object itself, calling the method list on the instance.

Routines supplied by class Mu

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

(Mu) method defined

Declared as

multi method defined(   --> Bool:D)

Returns False on the type object, and True otherwise.

say Int.defined;                # OUTPUT: «False␤» 
say 42.defined;                 # OUTPUT: «True␤» 

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

sub fails() { fail 'oh noe' };
say fails().defined;            # OUTPUT: «False␤» 

(Mu) routine defined

Declared as

multi sub    defined(Mu --> Bool:D)

invokes the .defined method on the object and returns its result.

(Mu) routine isa

multi method isa(Mu $type     --> Bool:D)
multi method isa(Str:D $type  --> Bool:D)

Returns True if the invocant is an instance of class $type, a subset type or a derived class (through inheritance) of $type.

my $i = 17;
say $i.isa("Int");   # OUTPUT: «True␤» 
say $i.isa(Any);     # OUTPUT: «True␤» 

A more idiomatic way to do this is to use the smartmatch operator ~~ instead.

my $s = "String";
say $s ~~ Str;       # OUTPUT: «True␤» 

(Mu) routine does

method does(Mu $type --> Bool:D)

Returns True if and only if the invocant conforms to type $type.

my $d ='2016-06-03');
say $d.does(Dateish);             # True    (Date does role Dateish) 
say $d.does(Any);                 # True    (Date is a subclass of Any) 
say $d.does(DateTime);            # False   (Date is not a subclass of DateTime) 

Using the smart match operator ~~ is a more idiomatic alternative.

my $d ='2016-06-03');
say $d ~~ Dateish;                # OUTPUT: «True␤» 
say $d ~~ Any;                    # OUTPUT: «True␤» 
say $d ~~ DateTime;               # OUTPUT: «False␤» 

(Mu) routine Bool

multi sub    Bool(Mu --> Bool:D)
multi method Bool(   --> 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;                    # OUTPUT: «False␤» 
say;                # OUTPUT: «True␤» 
say [123].Bool;             # OUTPUT: «True␤» 
say [].Bool;                    # OUTPUT: «False␤» 
say %hash => 'full' ).Bool;   # OUTPUT: «True␤» 
say {}.Bool;                    # OUTPUT: «False␤» 
say "".Bool;                    # OUTPUT: «False␤» 
say 0.Bool;                     # OUTPUT: «False␤» 
say 1.Bool;                     # OUTPUT: «True␤» 
say "0".Bool;                   # OUTPUT: «True␤» 

(Mu) method Capture

Declared as:

method Capture(Mu:D: --> Capture:D)

Returns a Capture with named arguments corresponding to invocant's public attributes:

class Foo {
    has $.foo = 42;
    has $.bar = 70;
    method bar { 'something else' }
}.new.Capture.say# OUTPUT: «\(:bar("something else"), :foo(42))␤» 

(Mu) method Str

multi method Str(--> 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. 

(Mu) routine gist

multi sub    gist(+args --> Str)
multi method gist(   --> Str)

Returns a string representation of the invocant, optimized for fast recognition by humans. As such lists will be truncated at 100 elements. Use .perl to get all elements.

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 that may truncate output.

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

say Mu.gist;        # OUTPUT: «(Mu)␤» 
say;    # OUTPUT: «␤» 

(Mu) routine perl

multi method perl(--> 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

(Mu) method item

method item(Mu \item:is raw

Forces the invocant to be evaluated in item context and returns the value of it.

say [1,2,3].item.perl;          # OUTPUT: «$[1, 2, 3]␤» 
say %apple => 10 ).item.perl# OUTPUT: «${:apple(10)}␤» 
say "abc".item.perl;            # OUTPUT: «"abc"␤» 

(Mu) method self

method self(--> Mu)

Returns the object it is called on.

(Mu) method clone

method clone(*%twiddles)

Creates a shallow clone of the invocant, including shallow cloning of private attributes. Alternative values for public attributes can be provided via named arguments with names matching the attributes' names.

class Point2D {
    has ($.x$.y);
    multi method gist(Point2D:D:{
my $p = => 2=> 3);
say $p;                     # OUTPUT: «Point(2, 3)␤» 
say $p.clone(=> -5);      # OUTPUT: «Point(2, -5)␤» 

Note that .clone does not go the extra mile to shallow-copy @. and %. sigiled attributes and, if modified, the modifications will still be available in the original object:

class Foo {
    has $.foo is rw = 42;
    has &.boo is rw = { say "Hi" };
    has       = <a b>;
    has %.baz       = <a b c d>;
my $o1 =;
with my $o2 = $o1.clone {
    .foo = 70;
    .bar = <Z Y>;
    .baz = <Z Y X W>;
    .boo = { say "Bye" };
# Hash and Array attribute modifications in clone appear in original as well: 
say $o1;    # OUTPUT: « => 42, bar => ["Z", "Y"], baz => {:X("W"), :Z("Y")}, …␤» 
say $o2;    # OUTPUT: « => 70, bar => ["Z", "Y"], baz => {:X("W"), :Z("Y")}, …␤» 
$; # OUTPUT: «Hi␤» 
$; # OUTPUT: «Bye␤» 

To clone those, you could implement your own .clone that clones the appropriate attributes and passes the new values to Mu.clone, for example, via nextwith. Alternatively, your own .clone could clone self first (using self.Mu::clone or callsame) and then manipulate the clone as needed, before returning it.

class Bar {
    has = <a b>;
    has = <a b c d>;
    method clone { nextwith :foo(@!foo.clone:bar(%!bar.clone}
my $o1 =;
with my $o2 = $o1.clone {
    .foo = <Z Y>;
    .bar = <Z Y X W>;
# Hash and Array attribute modifications in clone do not affect original: 
say $o1# OUTPUT: « => ["a", "b"], bar => {:a("b"), :c("d")})␤» 
say $o2# OUTPUT: « => ["Z", "Y"], bar => {:X("W"), :Z("Y")})␤» 

(Mu) 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.

(Mu) method bless

method bless(*%attrinit --> 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{
my $p =;

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

(Mu) method CREATE

method CREATE(--> Mu:D)

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

say Mu.CREATE.defined;  # OUTPUT: «True␤» 

(Mu) method print

multi method print(--> Bool:D)

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

"abc\n".print;          # RESULT: «abc␤» 

(Mu) method put

multi method put(--> Bool:D)

Prints value to $*OUT, adding a newline at end, and if necessary, stringifying non-Str object using the .Str method.

"abc".put;              # RESULT: «abc␤» 

(Mu) method say

multi method say(--> Bool:D)

Prints value to $*OUT after stringification using gist method with newline at end. To produce machine readable output use .put.

say 42;                 # OUTPUT: «42␤» 

(Mu) 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;           # OUTPUT: «True␤» 
say 42 ~~ Int;          # OUTPUT: «True␤» 
say 42 ~~ Str;          # OUTPUT: «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.

(Mu) method WHICH

multi method WHICH(--> 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;       # OUTPUT: «True␤» 

(Mu) method WHERE

method WHERE(--> Int)

Returns an Int representing the memory address of the object.

(Mu) method WHY

multi method WHY(--> Pod::Block::Declarator)

Returns the attached Pod::Block::Declarator.

For instance:

#| Initiate a specified spell normally 
sub cast(Spell $s{
#= (do not use for class 7 spells) 
say &cast.WHY;
# OUTPUT: «Initiate a specified spell normally␤(do not use for class 7 spells)␤» 

See Pod declarator blocks for details about attaching Pod to variables, classes, functions, methods, etc.

(Mu) 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.

See Exporting and Selective Importing Modules for more details.

(Mu) method return

method return()

The method return will stop execution of a subroutine or method, run all relevant phasers and provide invocant as a return value to the caller. If a return type constraint is provided it will be checked unless the return value is Nil. A control exception is raised and can be caught with CONTROL.

sub f { (1|2|3).return };
say f(); # OUTPUT: «any(1, 2, 3)␤» 

(Mu) method return-rw

Same as method return except that return-rw returns a writable container to the invocant (see more details here: return-rw).

(Mu) method emit

method emit()

Emits the invocant into the enclosing supply or react block.

react { whenever supply { .emit for "foo"42.5 } {
    say "received {.^name} ($_)";
# received Str (foo) 
# received Int (42) 
# received Rat (0.5) 

(Mu) method take

method take()

Returns the invocant in the enclosing gather block.

sub insert($sep+@list{
    gather for @list {
        FIRST .takenext;
        take slip $sep.item
say insert ':', <a b c>;
# OUTPUT: «(a : b : c)␤» 

(Mu) routine take

sub take(\item)

Takes the given item and passes it to the enclosing gather block.

#| randomly select numbers for lotto 
my $num-selected-numbers = 6;
my $max-lotto-numbers = 49;
gather for ^$num-selected-numbers {
    take (1 .. $max-lotto-numbers).pick(1);
}.say;    # six random values 

(Mu) routine take-rw

sub take-rw(\item)

Returns the given item to the enclosing gather block, without introducing a new container.

my @a = 1...3;
sub f(@list){ gather for @list { take-rw $_ } };
for f(@a{ $_++ };
say @a;
# OUTPUT: «[2 3 4]␤» 

(Mu) method so

method so()

Returns a Bool value representing the logical non-negation of an expression. One can use this method similarly to the English sentence: "If that is so, then do this thing". For instance,

my @args = <-a -e -b -v>;
my $verbose-selected = any(@argseq '-v' | '-V';
if $ {
    say "Verbose option detected in arguments";
} # OUTPUT: «Verbose option detected in arguments␤» 

(Mu) method not

method not()

Returns a Bool value representing the logical negation of an expression. Thus it is the opposite of so.

my @args = <-a -e -b>;
my $verbose-selected = any(@argseq '-v' | '-V';
if $verbose-selected.not {
    say "Verbose option not present in arguments";
} # OUTPUT: «Verbose option not present in arguments␤» 

Since there is also a prefix version of not, the above code reads better like so:

my @args = <-a -e -b>;
my $verbose-selected = any(@argseq '-v' | '-V';
if not $verbose-selected {
    say "Verbose option not present in arguments";
} # OUTPUT: «Verbose option not present in arguments␤»