$ perl -MO=Concise -e 'q{abc}'
3  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
-     <0> ex-const v ->3
-e syntax OK
$ perl -MO=Concise -e 'qq{abc}'
3  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
-     <0> ex-const v ->3
-e syntax OK