BEGIN {

    my %mask = ( q{"} => q{"***"},  q{'} => q{'***'}, );

    my $connector = qr{ => | : }xms;

    sub elide {

        my ($key,     # pattern: arm sensitive sub-string elision
            $string,
            ) = @_;

        $string =~ s{
            ((?<! \\) ['"]) $key \g-1 \s*
            $connector \s*
            \K
            \g-1 ((?! \g-2 | \\) .)* (?: \\. (?2)*)* \g-2
            }
            {$mask{$1}}xmsg;

        return $string;

        }

    }  # end BEGIN block