routine elems
Documentation for routine elems assembled from the following types:
language documentation Subscripts
From Subscripts
(Subscripts) method elems
multi method elems(::?CLASS:)
Expected to return a number indicating how many subscriptable elements there are in the object. May be called by users directly, and is also called by postcircumfix [ ] when indexing elements from the end, as in @foo[*-1].
If not implemented, your type will inherit the default implementation from Any that always returns 1 for defined invocants - which is most likely not what you want. So if the number of elements cannot be known for your positional type, add an implementation that fails or dies, to avoid silently doing the wrong thing.
class List
From List
(List) routine elems
Defined as:
sub elems( --> Int)method elems(List: --> Int)
Returns the number of elements in the list.
say (1,2,3,4).elems; # OUTPUT: «4»
class Capture
From Capture
(Capture) method elems
Defined as:
method elems(Capture: --> Int)
Returns the number of positional elements in the Capture.
my Capture = \(2, 3, 5, apples => (red => 2));say .elems; # OUTPUT: «3»
class Supply
From Supply
(Supply) method elems
method elems(Supply: ? --> Supply)
Creates a new supply in which changes to the number of values seen are emitted. It optionally also takes an interval (in seconds) if you only want to be updated every so many seconds.
class Range
From Range
(Range) method elems
method elems(Range: --> Numeric)
Returns the number of elements in the range, e.g. when being iterated over, or when used as a List. Returns 0 if the start point is larger than the end point, including when the start point was specified as ∞. Fails when the Range is lazy, including when the end point was specified as ∞ or either end point was specified as *.
say (1..5).elems; # OUTPUT: «5»say (1^..^5).elems; # OUTPUT: «3»
class Any
From Any
(Any) method elems
Defined as:
multi method elems(Any: --> 1)multi method elems(Any:)
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»say Whatever.elems ; # OUTPUT: «1»
It will also return 1 for classes.
role Baggy
From Baggy
(Baggy) method elems
Defined as:
method elems(Baggy: --> Int)
Returns the number of elements in the Baggy object without taking the individual elements weight into account.
my = bag <eggs spam spam spam>;say .elems; # OUTPUT: «2»my = ("b" => 9.4, "b" => 2).MixHash;say .elems; # OUTPUT: «1»
role Setty
From Setty
(Setty) method elems
method elems(--> Int)
The number of elements of the set.
class Array
From Array
(Array) method elems
Defined as:
method elems(Array: --> Int)
Returns the number of elements in the invocant. Throws X::Cannot::Lazy exception if the invocant is lazy. For shaped arrays, returns the outer dimension; see shape if you need information for all dimensions.
say [<foo bar ber>] .elems; # OUTPUT: «3»say (my [42;3;70]).elems; # OUTPUT: «42»try [-∞...∞].elems;say $!.^name; # OUTPUT: «X::Cannot::Lazy»
class Uni
From Uni
(Uni) method elems
method elems(Uni: --> Int)
Returns the number of codepoints in the invocant.
class Seq
From Seq
(Seq) method elems
method elems(Seq:)
Returns the number of values in the sequence. If this number cannot be predicted, the Seq is cached and evaluated till the end.
Because an infinite sequence cannot be evaluated till the end, such a sequence should be declared lazy. Calling .elems on a lazy Seq fails with X::Cannot::Lazy.
role Blob
From Blob
(Blob) method elems
Defined as:
multi method elems(Blob:)multi method elems(Blob: --> 1)
Returns the number of elements of the buffer.
my = Blob.new([1, 2, 3]);say .elems; # OUTPUT: «3»
It will also return 1 on the class object.
class Map
From Map
(Map) method elems
Defined as:
method elems(Map: --> Int)
Returns the number of pairs stored in the Map.
my = Map.new('a', 1, 'b', 2);say .elems; # OUTPUT: «2»
role Positional
From Positional
(Positional) method elems
method elems()
Should return the number of available elements in the instantiated object.
class Metamodel::EnumHOW
From Metamodel::EnumHOW
(Metamodel::EnumHOW) method elems
method elems()
Returns the number of values.
<10 20>;say Numbers.^elems; # OUTPUT: 2