Following on from ikegamis suggestion, you could (possibly i.e. if it suits) assert the uniformity of the list by treating all (sequences of) non-alpha numeric chars as delimiters:

use Data::Dumper;
my @els = '[1,2,3]' =~ /(\w+)/g;
print Dumper \@els;
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$VAR1 = [
          '1',
          '2',
          '3'
        ];
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