Rules / Types, classes & roles / composite

Sequence Reference

Common methods of sequences

What it is #

Position in the hierarchy #

Inherits from—
Does—
Consumed bySeq, RaceSeq, HyperSeq

Routines #

Signatures are reproduced from the documentation, including their declared return types. A routine listed here is part of the type's published interface; whether Raku++ implements it is a separate question, answered by the examples below.

method Str #

multi method Str(::?CLASS:D:)

Stringifies the cached sequence.

method Stringy #

multi method Stringy(::?CLASS:D:)

Calls .Stringy on the cached sequence.

method Numeric #

method Numeric(::?CLASS:D:)

Returns the number of elements in the cached sequence.

method AT-POS #

multi method AT-POS(::?CLASS:D: Int:D $idx)
multi method AT-POS(::?CLASS:D: int $idx)

Returns the element at position $idx in the cached sequence.

method EXISTS-POS #

multi method EXISTS-POS(::?CLASS:D: Int:D $idx)
multi method EXISTS-POS(::?CLASS:D: int $idx)

Returns a Bool indicating whether there is an element at position $idx in the cached sequence.

method eager #

method eager(::?CLASS:D: --> List:D)

Returns List:D.

Returns an eagerly evaluated List based on the invocant sequence, and marks it as consumed. If called on an already consumed Seq, throws an error of type X::Seq::Consumed.

method fmt #

method fmt($format = '%s', $separator = ' ' --> Str:D)

Returns Str:D.

Formats the cached sequence.

method gist #

multi method gist(::?CLASS:D:)

Returns the gist of the cached sequence.

Examples, run three ways #

Every example below comes from the official documentation, together with the output that documentation asserts. Each was then executed by Rakudo and by Raku++ when this page was built. Where the three agree, one result is shown; where they do not, all three are — because which of them is wrong is exactly the information worth having.

1 doc-drift · 2 no-output · 1 not-runnable

role Sequence does PositionalBindFailover { }

Not executed: the documentation states no expected output for this example.

my $s = lazy 1..5;

Not executed: the documentation states no expected output for this example.

say $s.is-lazy; # OUTPUT: «True␤»
say $s.eager;   # OUTPUT: «(1 2 3 4 5)␤»

Neither engine can run this in isolation — the example depends on context from the surrounding text.

say $s.eager;
CATCH {
    when X::Seq::Consumed {
        say 'Throws exception if already consumed';
    }
}
# OUTPUT: «Throws exception if already consumed␤»
Documentation
Throws exception if already consumed
Rakudo
Raku++

Both engines agree; the documentation states something else. Trust the engines.