>perl -MO=Concise -e"use strict; print 'a'"
6  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 2 -e:1) v/2 ->3
5     <@> print vK ->6
3        <0> pushmark s ->4
4        <$> const[PV "a"] s ->5
-e syntax OK