$ perl -MO=Concise,-exec -MDevel::Peek -we'Dump 1; sub foo{Dump $_[0];$_[0]=1} foo(1)' 1 <0> enter 2 <;> nextstate(main 44 -e:1) v:{ 3 <$> const[IV 1] s 4 <2> Devel_Peek_Dump vK/1 5 <;> nextstate(main 46 -e:1) v:{ 6 <0> pushmark s 7 <$> const[IV 1] sM 8 <#> gv[IV \&main::foo] s 9 <1> entersub vKS a <@> leave[1 ref] vKP/REFC -e syntax OK #### $ perl -MO=Concise,-exec -MDevel::Peek -we'Dump 1+1; sub foo{Dump $_[0];$_[0]=1} foo(1+1)' 1 <0> enter 2 <;> nextstate(main 44 -e:1) v:{ 3 <$> const[IV 2] s/FOLD 4 <2> Devel_Peek_Dump vK/1 5 <;> nextstate(main 46 -e:1) v:{ 6 <0> pushmark s 7 <$> const[IV 2] sM/FOLD 8 <#> gv[IV \&main::foo] s 9 <1> entersub vKS a <@> leave[1 ref] vKP/REFC -e syntax OK #### $ perl -MDevel::Peek -e'Dump(${\1})' SV = IV(0x8549e4010) at 0x8549e4020 REFCNT = 1 FLAGS = (IOK,READONLY,PROTECT,pIOK) IV = 1 $ perl -MDevel::Peek -e'Dump(${\(1+1)})' SV = IV(0x7ed5d4d610) at 0x7ed5d4d620 REFCNT = 1 FLAGS = (IOK,pIOK) IV = 2 $ perl -MDevel::Peek -e'Dump($_) for 1' SV = IV(0x151c4b8240) at 0x151c4b8250 REFCNT = 2 FLAGS = (IOK,READONLY,PROTECT,pIOK) IV = 1 $ perl -MDevel::Peek -e'Dump($_) for 1+1' SV = IV(0x567114cd90) at 0x567114cda0 REFCNT = 1 FLAGS = (IOK,pIOK) IV = 2