c:\@Work\Perl>perl -wMstrict -le
"my $s = qq{a ${ \str('tilt2') } operation needs @{[ str('x') ]} help};
 print qq{'$s'};
 ;;
 sub str {
   my ($s) = @_;
   ;;
   return
     $s eq 'level3' ? 'level3 stage' :
     $s eq 'tilt2'  ? 'tilt2 snafu'  :
     ! defined $s   ? 'undefined'    :
     qq{Edit '$s'}
     ;
   }
"
'a tilt2 snafu operation needs Edit 'x' help'