routine new

Documentation for routine new assembled from the following types:

class X::NYI

From X::NYI

(X::NYI) method new

method new:$feature:$did-you-mean:$workaround)

This is the default constructor for X:NYI which can take three parameters with obvious meanings.

class Nothing {
    method ventured$sub**@args{
        X::NYI.newfeature => &?,
                    did-you-mean => "gained",
                    workaround => "Implement it yourself" ).throw;
my $nothing =;

In this case, we are throwing an exception that indicates that the ventured routine has not been implemented; we use the generic &? to not tie the exception to the method name in case it is changed later on. This code effectively throws this exception

# ventured not yet implemented. Sorry. 
# Did you mean: gained? 
# Workaround: Implement it yourself 
#   in method ventured at NYI.p6 line 6 
#   in block <unit> at NYI.p6 line 14 

Using the exception properties, it composes the message that we see there.

class Map

From Map

(Map) method new

Defined as:

method new(*@args)

Creates a new Map from a list of alternating keys and values, with the same semantics as described in the Hashes and maps documentation, but also accepts Pairs instead of separate keys and values. Use the grouping operator or quote the key to ensure that a literal pair is not interpreted as a named argument.

my %h ='a'1'b'2);
# WRONG: :b(2) interpreted as named argument 
say'a'1:b(2)).keys# OUTPUT: «(a)␤» 
# RIGHT: :b(2) interpreted as Pair because of extra parentheses 
say ('a'1:b(2)) ).keys.sort# OUTPUT: «(a b)␤» 
# RIGHT: 'b' => 2 always creates a Pair 
say'a'1'b' => 2).keys.sort# OUTPUT: «(a b)␤»

A shorthand syntax for creating Maps is provided:

my %h is Map = 'a'1'b'2;

class Seq

From Seq

(Seq) method new

proto method new(Seq: |{*}
multi method new(Seq: Iterator:D $iter)
multi method new(Seq:)

Creates a new Seq object from the supplied iterator passed as the single argument. Creates an empty Seq if called with no argument.

class IO::CatHandle

From IO::CatHandle

(IO::CatHandle) method new

Defined as:

method new(*@handles:&on-switch:$chomp = True,
           :$nl-in = ["\n""\r\n"], Str :$encodingBool :$bin)

Creates a new IO::CatHandle object.

The @handles positional argument indicates a source of handles for the IO::CatHandle to read from and can deal with a mixed collection of Cool, IO::Path, and IO::Handle (including IO::Pipe) objects. As input from IO::CatHandle is processed (so operations won't happen during .new call, but only when @handles' data is needed), it will walk through the @handles list, processing each argument as follows:

In short, all the @handles end up as IO::Handle objects opened in the same mode and with the same attributes as the invocant IO::CatHandle.

See .on-switch method for details on the :&on-switch named argument, which by default is not set.

The :$encoding named argument specifies the handle's encoding and accepts the same values as IO::Handle.encoding. Set :$bin named argument to True if you wish the handle to be in binary mode. Attempting to specify both a defined :$encoding and a True :$bin is a fatal error resulting in X::IO::BinaryAndEncoding exception thrown. If neither :$encoding is set nor :$bin set to a true value, the handle will default to utf8 encoding.

The :$chomp and :$nl-in arguments have the same meaning as in IO::Handle and take and default to the same values.

class IO::Path

From IO::Path

(IO::Path) method new

Defined as:

multi method new(Str:D $pathIO::Spec :$SPEC = $*SPECStr() :$CWD = $*CWD)
multi method new(
    :$basename!:$dirname = '.':$volume = ''
    IO::Spec :$SPEC = $*SPECStr() :$CWD = $*CWD

Creates a new IO::Path object from a path string (which is being parsed for volume, directory name and basename), or from volume, directory name and basename passed as named arguments.

The path's operation will be performed using :$SPEC semantics (defaults to current $*SPEC) and will use :$CWD as the directory the path is relative to (defaults to $*CWD).

If $path includes the null byte, it will throw an Exception with a "Cannot use null character (U+0000) as part of the path" message.

class IO::Path::Cygwin

From IO::Path::Cygwin

(IO::Path::Cygwin) method new

Same as, except :$SPEC cannot be set and defaults to IO::Spec::Cygwin, regardless of the operating system the code is being run on.

class IO::Path::Parts

From IO::Path::Parts

(IO::Path::Parts) method new

method new(\volume, \dirname, \basename)

Create a new IO::Path::Parts object with \volume, \dirname and \basename as respectively the volume, directory name and basename parts.

class IO::Path::QNX

From IO::Path::QNX

(IO::Path::QNX) method new

Same as, except :$SPEC cannot be set and defaults to IO::Spec::QNX, regardless of the operating system the code is being run on.

class IO::Path::Unix

From IO::Path::Unix

(IO::Path::Unix) method new

Same as, except :$SPEC cannot be set and defaults to IO::Spec::Unix, regardless of the operating system the code is being run on.

class IO::Path::Win32

From IO::Path::Win32

(IO::Path::Win32) method new

Same as, except :$SPEC cannot be set and defaults to IO::Spec::Win32, regardless of the operating system the code is being run on.

class IO::Socket::INET

From IO::Socket::INET

(IO::Socket::INET) method new

multi method new(
        :$family = PF_INET,
        :$encoding = 'utf-8',
        :$nl-in = "\r\n",
    --> IO::Socket::INET:D)
multi method new(
        :$family = PF_INET,
        :$encoding = 'utf-8',
        :$nl-in = "\r\n",
    --> IO::Socket::INET:D)

Creates a new socket.

If :$listen is True, creates a new socket that listen on :$localhost (which can be an IP address or a domain name) on port :$localport; in other words the :$listen flag determines the server mode of the socket. Otherwise (i.e., :$listen is False), the new socket opens immediately a connection to :$host on port :$port.

:$family defaults to PF_INET constant for IPv4, and can be set to PF_INET6 constant for IPv6.

For text operations (such as method lines and method get), :$encoding specifies the encoding, and :$nl-in determines the character(s) that separate lines.

class IO::Special

From IO::Special

(IO::Special) method new

method new(:$!what!)

Takes a single required attribute what. It is unlikely that you will ever need to construct one of these objects yourself.

class Junction

From Junction

(Junction) method new

Defined as:

multi method new(Junction: \valuesStr :$type!)
multi method new(Junction: Str:D \type, \values)

These constructors build a new junction from the type that defines it and a set of values.

my $j =<Þor Oðinn Loki>type => "all");
my $n ="one"1..6 )

The main difference between the two multis is how the type of the Junction is passed as an argument; either positionally as the first argument, or as a named argument using type.

class CX::Warn

From CX::Warn

(CX::Warn) method new

CX::Warn objects are created when a warning is thrown in any block.

class Num

From Num

(Num) method new

Defined as

multi method new()
multi method new($n) without argument will create a Num with the value 0e0. With an argument, it will be coerced to Num and then returned.

say⅓); # OUTPUT: «0.3333333333333333␤»

class Proxy

From Proxy

(Proxy) method new

method new(:&FETCH!:&STORE! --> Proxy:D)

Creates a new Proxy object. &FETCH is called with one argument (the proxy object) when the value is accessed, and must return the value that the fetch produces. &STORE is called with two arguments (the proxy object, and the new value) when a new value is stored in the container.

class Proc

From Proc

(Proc) routine new

method new(Proc:U:
        :$in = '-',
        :$out = '-',
        :$err = '-',
        Bool :$bin = False,
        Bool :$chomp = True,
        Bool :$merge = False,
        Str:D :$enc = 'UTF-8',
        Str:D :$nl = "\n",
    --> Proc:D)
sub shell(
        :$in = '-',
        :$out = '-',
        :$err = '-',
        Bool :$bin = False,
        Bool :$chomp = True,
        Bool :$merge = False,
        Str:D :$enc = 'UTF-8',
        Str:D :$nl = "\n",
        :$cwd = $*CWD,
        Hash() :$env = %*ENV
    --> Proc:D)

new creates a new Proc object, whereas run or shell create one and spawn it with the command and arguments provided in @args or $cmd, respectively.

$in, $out and $err are the three standard streams of the to-be-launched program, and default to "-" meaning they inherit the stream from the parent process. Setting one (or more) of them to True makes the stream available as an IO::Pipe object of the same name, like for example $proc.out. You can set them to False to discard them. Or you can pass an existing IO::Handle object (for example IO::Pipe) in, in which case this handle is used for the stream.

Please bear in mind that the process streams reside in process variables, not in the dynamic variables that make them available to our programs. Thus, modifying the dynamic filehandle variables (such as $*OUT) inside the host process will have no effect in the spawned process, unlike $*CWD and $*ENV, whose changes will be actually reflected in it.

my $p-name = "/tmp/program.raku";
my $program = Q:to/END/; 
    #!/usr/bin/env raku
    $*OUT.say( qq/\t$*PROGRAM: This goes to standard output/ );
spurt $p-name$program;
$*OUT.put: "1. standard output before doing anything weird";
    temp $*OUT = open '/tmp/out.txt':w;
    $*OUT.put: "2. temp redefine standard output before this message";
    shell"raku $p-name" ).so;
$*OUT.put: "3. everything should be back to normal";
# 1. standard output before doing anything weird 
#     /tmp/program.raku: This goes to standard output 
# 3. everything should be back to normal 
# /tmp/out.txt will contain: 
# 2. temp redefine standard output before this message 

This program shows that the program spawned with shell is not using the temporary $*OUT value defined in the host process (redirected to /tmp/out.txt), but the initial STDOUT defined in the process.

$bin controls whether the streams are handled as binary (i.e. Blob object) or text (i.e. Str objects). If $bin is False, $enc holds the character encoding to encode strings sent to the input stream and decode binary data from the output and error streams.

With $chomp set to True, newlines are stripped from the output and err streams when reading with lines or get. $nl controls what your idea of a newline is.

If $merge is set to True, the standard output and error stream end up merged in $proc.out.

class Int

From Int

(Int) method new

Defined as:

multi method new(Any:U $type)
multi method new(Any:D \value --> Int:D)
multi method new(int   \value --> Int:D)

The first form will throw an exception; the second and third form will create an new Int from the actual integer value contained in the variable.

class ComplexStr

From ComplexStr

(ComplexStr) method new

method new(Complex $iStr $s)

The constructor requires both the Complex and the Str value, when constructing one directly the values can be whatever is required:

my $f =, "forty two (but complicated)");
say +$f# OUTPUT: «42+0i␤» 
say ~$f# OUTPUT: «"forty two (but complicated)"␤»

class Metamodel::PackageHOW

From Metamodel::PackageHOW

(Metamodel::PackageHOW) method new

Defined as:

method new(*%named)

Creates a new PackageHOW.

class Thread

From Thread

(Thread) method new

method new(:&code!Bool :$app_lifetime = FalseStr :$name = '<anon>' --> Thread:D)

Creates and returns a new Thread, without starting it yet. &code is the code that will be run in a separate thread.

$name is a user-specified string that identifies the thread.

If $app_lifetime is set to True, then the thread is killed when the main thread of the process terminates. If set to False, the process will only terminate when the thread has finished.

class IntStr

From IntStr

(IntStr) method new

method new(Int $iStr $s)

The constructor requires both the Int and the Str value, when constructing one directly the values can be whatever is required:

my $f ="forty two");
say +$f# OUTPUT: «42␤» 
say ~$f# OUTPUT: «"forty two"␤»

class Uni

From Uni

(Uni) method new

method new(*@codes --> Uni:D)

Creates a new Uni instance from the given codepoint numbers.

class Nil

From Nil

(Nil) method new

method new(*@)

Returns Nil

class Distribution::Hash

From Distribution::Hash

(Distribution::Hash) method new

method new($hash:$prefix)

Creates a new Distribution::Hash instance from the metadata contained in $hash. All paths in the metadata will be prefixed with :$prefix.

class Distribution::Path

From Distribution::Path

(Distribution::Path) method new

method new(IO::Path $prefixIO::Path :$meta-file = IO::Path)

Creates a new Distribution::Path instance from the META6.json file found at the given $prefix, and from which all paths in the metadata will be prefixed with. :$meta-file may optionally be passed if a filename other than META6.json needs to be used.

class Failure

From Failure

(Failure) method new

Defined as:

multi method new(Failure:D:)
multi method new(Failure:U:)
multi method new(Failure:U: Exception:D \exception)
multi method new(Failure:U: $payload)
multi method new(Failure:U: |cap (*@msg))

Returns a new Failure instance with payload given as argument. If called without arguments on a Failure object, it will throw; on a type value, it will create an empty Failure with no payload. The latter can be either an Exception or a payload for an Exception. A typical payload would be a Str with an error message. A list of payloads is also accepted.

my $e ='WELP‼');
say $e;
CATCH{ default { say .^name''.Str } }
# OUTPUT: «X::AdHoc: 2017-09-10T11:56:05.477237ZWELP‼␤»

class Telemetry::Sampler

From Telemetry::Sampler

(Telemetry::Sampler) method new

method new(Telemetry::Sampler: @instruments --> Telemetry::Sampler:D)

The new method takes a list of instruments. If no instruments are specified, then it will look at the RAKUDO_TELEMETRY_INSTRUMENTS environment variable to find specification of instruments. If that is not available either, then Telemetry::Instrument::Usage and Telemetry::Instrument::ThreadPool will be assumed.

Instruments can be specified by either the type object of the instrument class (e.g. Telemetry::Instrument::Usage) or by a string, in which case it will be automatically prefixed with "Telemetry::Instrument::", so "Usage" would be the same as Telemetry::Instrument::Usage.

class Mu

From Mu

(Mu) method new

multi method new(*%attrinit)
multi method new($*@)

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.

role Blob

From Blob

(Blob) method new

Defined as:

multi method new(Blob:)
multi method new(Blob: Blob:D $blob)
multi method new(Blob: int @values)
multi method new(Blob: @values)
multi method new(Blob: *@values)

Creates an empty Blob, or a new Blob from another Blob, or from a list of integers or values (which will have to be coerced into integers):

my $blob =[123]);
say<1 2 3>); # OUTPUT: «Blob:0x<01 02 03>␤»

class Complex

From Complex

(Complex) method new

Defined as:

multi method new(Real $reReal $im --> Complex:D)

Creates a new Complex object from real and imaginary parts.

my $complex =;
say $complex;    # OUTPUT: «1+1i␤»

When created without arguments, both parts are considered to be zero.

say OUTPUT: «0+0i␤»

class Date

From Date

(Date) method new

Defined as:

multi method new($year$month$day:&formatter --> Date:D)
multi method new(:$year!:$month = 1:$day = 1  --> Date:D)
multi method new(Str $date                        --> Date:D)
multi method new(Instant:D $dt                    --> Date:D)
multi method new(DateTime:D $dt                   --> Date:D)

Creates a new Date object, either from a triple of (year, month, day) that can be coerced to integers, or from a string of the form YYYY-MM-DD (ISO 8601), or from an Instant or DateTime object. Optionally accepts a formatter as a named parameter.

my $date =;
$date = => 2042month => 1day => 1);
$date ="2042-01-01");
$date = 1482155532);
$date =;

Since Rakudo 2022.03, the "day" argument can also be a callable, with * representing the last day in a month, and the possibility of getting to the day counting from the last one:

say*); # OUTPUT: «2042-02-28␤» 
say*); # OUTPUT: «2044-02-29␤»

class Supplier::Preserving

From Supplier::Preserving

(Supplier::Preserving) method new

method new()

The Supplier constructor.

class Version

From Version

(Version) method new

method new(Str:D $s)

Creates a Version from a string $s. The string is combed for the numeric, alphabetic, and wildcard components of the version object. Any characters other than alphanumerics and asterisks are assumed to be equivalent to a dot. A dot is also assumed between any adjacent numeric and alphabetic characters.

class RatStr

From RatStr

(RatStr) method new

method new(Rat $iStr $s)

The constructor requires both the Rat and the Str value, when constructing one directly the values can be whatever is required:

my $f ="forty two and a bit");
say +$f# OUTPUT: «42.1␤» 
say ~$f# OUTPUT: «"forty two and a bit"␤»

role Rational

From Rational

(Rational) method new

method new(NuT:D $numeratorDeT:D $denominator --> Rational:D)

Creates a new rational object from numerator and denominator, which it normalizes to the lowest terms. The $denominator can be zero, in which case the numerator is normalized to -1, 0, or 1 depending on whether the original is negative, zero, or positive, respectively.

class Semaphore

From Semaphore

(Semaphore) method new

method newint $permits )

Initialize the semaphore with the number of permitted accesses. E.g. when set to 2, program threads can pass the acquire method twice until it blocks on the third time acquire is called.

class Backtrace

From Backtrace

(Backtrace) method new

Defined as:

multi method new()
multi method new(Int:D $offset)
multi method new(Mu \ex)
multi method new(Mu \exInt:D $offset)
multi method new(List:D $bt)
multi method new(List:D $btInt:D $offset)

Creates a new backtrace, using its calling location as the origin of the backtrace or the $offset that is passed as a parameter. If an object or a list (that will already contain a backtrace in list form) is passed, they will be used instead of the current code.

my $backtrace =;

class Supplier

From Supplier

(Supplier) method new

method new()

The Supplier constructor.

class Pair

From Pair

(Pair) method new

Defined as:

multi method new(Pair: Mu  $keyMu  $value)
multi method new(Pair: Mu :$keyMu :$value)

Constructs a new Pair object.

class Proc::Async

From Proc::Async

(Proc::Async) method new

multi method new(*@ ($path*@args), :$w:$enc:$translate-nl:$arg0,
                 :$win-verbatim-args = False,
                 :$started = False --> Proc::Async:D)
multi method new(   :$path:@args,  :$w:$enc:$translate-nl:$arg0,
                 :$win-verbatim-args = False,
                 :$started = False --> Proc::Async:D)

Creates a new Proc::Async object with external program name or path $path and the command line arguments @args.

If :w is passed to new, then a pipe to the external program's standard input stream (stdin) is opened, to which you can write with write and say.

The :enc specifies the encoding for streams (can still be overridden in individual methods) and defaults to utf8.

If :translate-nl is set to True (default value), OS-specific newline terminators (e.g. \r\n on Windows) will be automatically translated to \n.

If :arg0 is set to a value, that value is passed as arg0 to the process instead of the program name.

The :started attribute is set by default to False, so that you need to start the command afterwards using .start. You probably don't want to do this if you want to bind any of the handlers, but it's OK if you just need to start a external program immediately.

On Windows the flag $win-verbatim-args disables all automatic quoting of process arguments. See this blog for more information on windows command quoting. The flag is ignored on all other platforms. The flag was introduced in Rakudo version 2020.06 and is not present in older releases. By default, it's set to False, in which case arguments will be quoted according to Microsoft convention.

class DateTime

From DateTime

(DateTime) method new

Defined as:

multi method new(Int :$year!Int :$month = 1Int :$day = 1,
                 Int :$hour = 0Int :$minute = 0:$second = 0,
                 Int :$timezone = 0:&formatter)
multi method new(Date :$date!,
                 Int :$hour = 0Int :$minute = 0:$second = 0,
                 Int :$timezone = 0:&formatter)
multi method new(Int() $yearInt() $monthInt() $day,
                 Int() $hourInt $minute$second,
                 Int() :$timezone = 0:&formatter)
multi method new(Instant:D $i,  :$timezone=0:&formatter)
multi method new(Numeric:D $posix,  :$timezone=0:&formatter)
multi method new(Str:D $format:$timezone=0:&formatter)

Creates a new DateTime object. One option for creating a new DateTime object is from the components (year, month, day, hour, ...) separately. Another is to pass a Date object for the date component, and specify the time component-wise. Yet another is to obtain the time from an Instant, and only supply the time zone and formatter. Or instead of an Instant you can supply an Numeric as a UNIX timestamp.

You can also supply a Str formatted in ISO 8601 timestamp notation or as a full RFC 3339 date and time. Strings should be formatted as yyyy-mm-ddThh:mm:ssZ or yyyy-mm-ddThh:mm:ss+0100. We are somewhat less restrictive than the ISO 8601 standard, as we allow Unicode digits and mixing of condensed and extended time formats.

An invalid input string throws an exception of type X::Temporal::InvalidFormat. If you supply a string that includes a time zone and supply the timezone named argument, an exception of type X::DateTime::TimezoneClash is thrown.

my $datetime = => 2015,
                            month => 1,
                            day => 1,
                            hour => 1,
                            minute => 1,
                            second => 1,
                            timezone => 1);
$datetime = =>'2015-12-24'),
                         hour => 1,
                         minute => 1,
                         second => 1,
                         timezone => 1);
$datetime = First January of 2015 
                         111);   # Hour, minute, second with default time zone 
$datetime =;                       # Instant. 
# from a Unix timestamp 
say $datetime =;          # OUTPUT: «2016-08-10T18:26:23.300000Z␤» 
$datetime ="2015-01-01T03:17:30+0500"# Formatted string

Since Rakudo release 2022.03, the day parameter can be a Callable, with * returning the last day in the month, and *-n returning the last but n.

class NumStr

From NumStr

(NumStr) method new

method new(Num $iStr $s)

The constructor requires both the Num and the Str value, when constructing one directly the values can be whatever is required:

my $f ="forty two and a bit");
say +$f# OUTPUT: «42.1␤» 
say ~$f# OUTPUT: «"forty two and a bit"␤»