How to remove duplicates items in list (Raku)

Question

FAQ: In Raku, how to remove duplicates from a list to only get unique values?

my $arr = [1, 2, 3, 2, 3, 1, 1, 0];
# desired output [1, 2, 3, 0]

Tinmarino · Accepted Answer · 2020-03-25 16:53:50Z

8

@arr.unique  # (1 2 3 0)

my %unique = map {$_ => 1}, @arr;
%unique.keys;  # (0 1 2 3) do not rely on order

set(@arr).keys

Links:
- Answer on Roseta Code
- Hash solution on Think Perl6
- Same question for Perl, Python -> always same methods: a Hash or a Set

answered Mar 25, 2020 at 16:53

Tinmarino

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1 Comment

Note that the .unique solution is probably the most performant and preserves order.