/.(?{ do_smth( $& ) })(*FAIL)/ for @lines;

##</code><code>##

	/.(?{ do_smth( $& ) })(*FAIL)/

##</code><code>##

	do_smth( $& ) while /./g;

##</code><code>##

	do_smth( $& ) while /./g for @lines;  # syntax error

##</code><code>##

	do{ do_smth( $& ) while /./g } for @lines;

##</code><code>##

	s/./ do_smth( $& ) /ger for @lines;