Does it even count as an esolang feature if it was a real feature in a commonly-used language for years? https://perldoc.perl.org/5.20.0/arybase https://perldo

Does it even count as an esolang feature if it was a real feature in a commonly-used language for years? https://perldoc.perl.org/5.20.0/arybase https://perldoc.perl.org/5.20.0/arybase It was even more fun in Perl 4, when $[ was program-scoped o_O