(?{ my $v = eval $^N;
            say $i x $l,"->have number $v" if TRACE_JSON; 
            push_val($v); })
      )

##</code><code>##

(?{ push_number( $^N, $depth ); })
sub push_number {
...
TRACE( $depth, $msg );

##</code><code>##

          (?>(?&STRING)) # ratchet
          \s*+ # ratchet
            [^\\"]++ # ratchet
          )*+ # ratchet
          (?: 0 | [1-9]\d*+ # ratchet