$ perl -MO=Concise,-exec -e'grep { /x/ } @a'
1  <0> enter v
2  <;> nextstate(main 1 -e:1) v:{
3  <0> pushmark s
4  <#> gv[*a] s
5  <1> rv2av[t2] lKM/1
6  <@> grepstart K
7  <|> grepwhile(other->8)[t3] vK
8      <0> enter s
9      <;> nextstate(main 2 -e:1) v:{
a      </> match(/"x"/) s
b      <@> leave sKP
           goto 7
c  <@> leave[1 ref] vKP/REFC
-e syntax OK