$ perl -MO=Concise -e'use constant FOOBAR => scalar <STDIN>; print FOOBAR'
abc
6  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 102 -e:1) v:{ ->3
5     <@> print vK ->6
3        <0> pushmark s ->4
4        <$> const[PV "abc\n"] s ->5     # <---