perl -MO=Concise,f -e 'sub f { my $x = shift; sub () { $x } };' main::f: 9 <1> leavesub[1 ref] K/REFC,1 ->(end) - <@> lineseq KP ->9 1 <;> nextstate(main 1 -e:1) v ->2 4 <2> sassign vKS/2 ->5 2 <0> shift s* ->3 3 <0> padsv[$x:1,3] sRM*/LVINTRO ->4 5 <;> nextstate(main 3 -e:1) v ->6 8 <1> refgen K/1 ->9 - <1> ex-list lKRM ->8 6 <0> pushmark sRM ->7 7 <$> anoncode[CV ""] lRM ->8 -e syntax OK