perl - How to enumerate all possible combinations of elements -

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i want enumerate possible combinations of elements array. example: have array:

$r = ('a1','a2','a3' ...).

i want print combinations of element arrays: a1a2, a1a3, a1a2a3, etc . a1a2 != a2a1, a1a2a3 != a1a3a2 ...

it turns out there's a module that:

use math::combinatorics;  @r = qw(a1 a2 a3 ...); #@all_combinations_of_r = map { combine($_,@r) } 1..@r; @all_permutations_of_r = map { permute(@$_) } map { combine($_,@r) } 1..@r;

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