Methods by type

List methods

Full

Reshape and query lists — unique, reverse, rotor, head/tail, classify.

Positional values (List, Array, Seq) share a rich method set for reshaping and summarising. A representative handful:

unique and reverse #

say (3, 1, 2, 1).unique;
say (1, 2, 3).reverse;
Output
(3 1 2)
(3 2 1)

unique drops later duplicates while keeping first-seen order; reverse flips the sequence.

rotor — fixed-size chunks #

rotor(n) batches a list into sublists of n elements.

say (1..6).rotor(2);
Output
((1 2) (3 4) (5 6))

head, tail, minmax #

say (1, 2, 3, 4).head(2);
say (1, 2, 3, 4).tail(2);
say (5, 3, 8, 1).minmax;
Output
(1 2)
(3 4)
1..8

classify — group by a key #

classify runs a block per element and groups elements under the returned key, producing a hash of lists.

my %g = (1..6).classify({ $_ %% 2 ?? "even" !! "odd" });
say %g<even>;
say %g<odd>;
Output
[2 4 6]
[1 3 5]

Notes #