TITLE

Indicate endianness (6.d, 2018.12 and later)


SUBTITLE

enum Endian <NativeEndian LittleEndian BigEndian>;


X<|Reference,NativeEndian>
X<|Reference,LittleEndian>
X<|Reference,BigEndian>
X<|Reference,Endian>
An enum for indicating endianness, specifically with methods on C<blob8> and
C<buf8>.  Consists of C<NativeEndian>, C<LittleEndian> and C<BigEndian>.


head

multi method Numeric(Endian:D --> Int:D)


Returns the value part of the C<enum> pair.


say NativeEndian.Numeric;    # OUTPUT: «0␤»
say LittleEndian.Numeric;    # OUTPUT: «1␤»
say BigEndian.Numeric;       # OUTPUT: «2␤»


Note that the actual numeric values are subject to change.  So please use
the named values instead.


root

Logical Boolean


enum Bool


para

L<Examples| file:../examples/index.podlite>


L<Download |file:../download/index.podlite>


React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


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FOOTER

enum Endian


Working with the role behind the enum type


This is the role implemented by the enum-pairs in the
L<C<enum> type|/language/typesystem#enum>. In general, it is used to create
constant sets,
the elements of which become also constant symbols in the current namespace and
to establish a relationship between the symbols belonging to the same set. In
general, you will find C<Enumeration> in L<enum|/language/typesystem#enum>
types:


    enum norse-gods <Þor Oðin Loki>;
    my $one-of-them = norse-gods.pick;
    say $one-of-them ~~ Enumeration; # OUTPUT: «True␤»


but nothing prevents you from using it in your own programs if you want to
restrict somehow the relationship between the key and the value:


code

=begin code
class DNA does Enumeration {
    my %pairings = %( A => "T",
                      T => "A",
                      C => "G",
                      G => "C" );

    method new( $base-pair where "A" | "C" | "G" | "T" )  {
        self.bless( key => $base-pair,
                    value => %pairings{$base-pair});
    }

    multi method gist(::?CLASS:D:) {
        return "$!key → $!value";
    }

}

enum Chain ();
constant length = 16;
for <A C G T>.roll( length ) -> $letter {
    my DNA $base = DNA.new( $letter );
    Chain.HOW.add_enum_value( Chain, $base );
}

for ^length {
    my $base = Chain.pick;
    say "{$base.key} and {$base.value}";
}
=end code


In this code, C<DNA> consumes the C<Enumeration> role, which is from this point
of view a pair of key and value; we can use the generated C<DNA> objects to
compose an C<enum> type from which elements can be picked one by one, with the
output shown below.


=begin code :lang<text>
T and A
C and G
T and A
# and so on...
=end code


An item would smartmatch the enum class, but not the other way round:


As of release 2021.04 of the Rakudo compiler, an enum class can be
considered as an instantiated L<C<Map>|/type/Map> object.  This means
you can use the
L<keys|/type/Map#method_keys>,
L<values|/type/Map#method_values>,
L<kv|/type/Map#method_kv>,
L<pairs|/type/Map#method_pairs>,
L<antipairs|/type/Map#method_antipairs>,
L<invert|/type/Map#method_invert>
on an enum class and get the expected result.


    enum Norse-gods <Þor Oðin Freija>;
    say Norse-gods.keys; # OUTPUT: «(Þor Oðin Freija)␤»


Returns a L<C<Map>|/type/Map> of enum values. Works both on the enum type
and any key.


    enum Mass ( mg => 1/1000, g => 1/1, kg => 1000/1 );
    say Mass.enums; # OUTPUT: «Map.new((g => 1, kg => 1000, mg => 0.001))␤»
    say g.enums;    # OUTPUT: «Map.new((g => 1, kg => 1000, mg => 0.001))␤»


    enum Norse-gods <Þor Oðin Freija>;
    say Freija.key; # OUTPUT: «Freija␤»


    enum Norse-gods <Þor Oðin Freija>;
    say Oðin.value; # OUTPUT: «1␤»


The C<value> is assigned automatically by the C<enum> type starting at 0.
C<Oðin> gets 1 since it is the second in the C<enum>.


Returns a list with key and value of the enum-pair.


Returns an C<Enumeration> instance given an enum value.


    enum Mass ( mg => 1/1000, g => 1/1, kg => 1000/1 );
    say Mass(1/1000); # OUTPUT: mg


    multi method pick(::?CLASS:U:)
    multi method pick(::?CLASS:U: \n)
    multi method pick(::?CLASS:D: *@pos)


It works on the defined class, selecting one element and eliminating it.


say Norse-gods.pick() for ^3;  # OUTPUT: «Þor␤Freija␤Oðin␤»


    multi method roll(::?CLASS:U:)
    multi method roll(::?CLASS:U: \n)
    multi method roll(::?CLASS:D: *@pos)


They work on the defined class selecting one or C<n> elements without
eliminating them.


say Norse-gods.roll() for ^3;  # OUTPUT: «Freija␤Freija␤Oðin␤»


role Enumeration


C<Encoding::Registry> is initialized with a list of encoding that is
available for any Raku application, namely:


item

Register a new L<C<Encoding>|/type/Encoding>.


X<|Types,Encoding::Encoder>
X<|Types,Encoding::Decoder>


Finds an encoding by its name. Returns an C<Encoding::Encoder> or
C<Encoding::Decoder>, depending on what had been registered.


Native integer


class int


Dual value number and string


class Allomorph


Thing/object


class Any


Abstract representation of a piece of source code


class AST


Integer (native storage at the platform's atomic operation size)


class atomicint


Code object with its own lexical scope


class Block


Captures the current frame state


class CallFrame


Code object


class Code


Encapsulates instructions about how strings should be sorted


class Collation


Information related to the compiler that is being used


class Compiler


Complex number


class Complex


Dual value complex number and string


class ComplexStr


Object that can be treated as both a string and number


class Cool


Scheduler that synchronously executes code on the current thread


class CurrentThreadScheduler


Calendar date


class Date


Calendar date with time


class DateTime


Distribution::Hash


class Distribution::Hash


Distribution::Locally


class Distribution::Locally


Distribution::Path


class Distribution::Path


Every one of the resources installed with a distribution


class Distribution::Resource


Length of time


class Duration


Rational number (arbitrary-precision)


class FatRat


Rakudo-specific class that wraps around code in other languages (generally NQP)


class ForeignCode


Convert values to a string given a format specification


class Format


Produce Callable for given format specification


class Formatter


An object for performing batches of work in parallel with ordered
output


class HyperSeq


Placeholder for multiple unspecified values/arguments


class HyperWhatever


Specific moment in time


class Instant


Integer (arbitrary-precision)


class Int


Dual value integer and string


class IntStr


Logical superposition of values


class Junction


Tagged location in the source code


class Label


A non-blocking, non-re-entrant, mutual exclusion lock


class Lock::Async


Compile-time routine


class Macro


Member function


class Method


The root of the Raku type hierarchy.


class Mu


Absence of a value or a benign failure


class Nil


Floating-point number


class Num


Number or object that can act as a number


role Numeric


Dual value floating-point number and string


class NumStr


Unique identification for an object


class ObjAt


Element of a Signature


class Parameter


Perl related information


class Perl


Item container with custom storage and retrieval


class Proxy


Performs batches of work in parallel without respecting original
order.


class RaceSeq


Raku related information


class Raku


Namespace for holding RakuAST related classes


package RakuAST


Contains the information of a RakuDoc block


class RakuAST::Doc::Block


Contains the declarator docs of a RakuAST object


class RakuAST::Doc::Declarator


Contains the information about RakuDoc markup


class RakuAST::Doc::Markup


Contains the information about a RakuDoc paragraph


class RakuAST::Doc::Paragraph


Rational number (limited-precision)


class Rat


Dual value rational number and string


class RatStr


Code object with its own lexical scope and return handling


class Routine


Holds all information needed to unwrap a wrapped routine.


class Routine::WrapHandle


A mostly transparent container used for indirections


class Scalar


Parameter list pattern


class Signature


String of characters


class Str


Contains the result of a string transformation.


class StrDistance


Subroutine


class Sub


Member function that is not inherited by subclasses


class Submethod


Collect performance state for analysis


class Telemetry


Instrument for collecting Thread data


class Telemetry::Instrument::Thread


Instrument for collecting ThreadPoolScheduler data


class Telemetry::Instrument::ThreadPool


Instrument for collecting getrusage data


class Telemetry::Instrument::Usage


Performance data over a period


class Telemetry::Period


Telemetry instrument pod


class Telemetry::Sampler


Unsigned integer (arbitrary-precision)


Subset UInt


Unique identification for value types


class ValueObjAt


Object representation of a variable for use in traits


class Variable


Module version descriptor


class Version


Placeholder for the value of an unspecified argument


class Whatever


Code object constructed by Whatever-priming


class WhateverCode


Management of available encodings


class Encoding::Registry


The Raku Knowledge Base


enum Endian

Methods

routine Numeric

See Also