>c:\progs\perl561\bin\perl -v

This is perl, v5.6.1 built for MSWin32-x86-multi-thread
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2001, Larry Wall

Binary build 635 provided by ActiveState Corp. http://www.ActiveState.com
Built 15:34:21 Feb  4 2003

...

>c:\progs\perl561\bin\perl -MO=Deparse -e"for my $s ( qw( a b c ) ) {}"
foreach my $s ('a', 'b', 'c') {
    ();
}
-e syntax OK

>c:\progs\perl561\bin\perl -MO=Concise -e"for my $s ( qw( a b c ) ) {}"
e  <@> leave[$s:5,7] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 7 -e:1) v ->3
d     <2> leaveloop vK/2 ->e
7        <{> enteriter(next->9 last->d redo->8)[$s:5,7] lK ->b
-           <0> ex-pushmark s ->3
-           <1> ex-list lKPM ->7
3              <0> pushmark sM ->4
4              <$> const(SPECIAL Null)[t2] sM ->5
5              <$> const(SPECIAL Null)[t3] sM ->6
6              <$> const(SPECIAL Null)[t4] sM ->7
-        <1> null vK/1 ->d
c           <|> and(other->8) vK/1 ->d
b              <0> iter s ->c
-              <@> lineseq vK ->-
8                 <0> stub v ->9
9                 <0> unstack v ->a
a                 <;> nextstate(main 7 -e:1) v ->b
-e syntax OK