my @aDone = map {
  push @aPending, $_;
  my @aNormalized;
  while (scalar(@aPending)) {
    my $sPending = shift @aPending;
    my $sNormalized = normalize($sPending, [@aPending]);
    if (!defined($sNormalized)) {
       #not enough information to normalize yet
       #so put the token back into the pending list
       unshift @aPending, $sPending;
       last;
    } 
    push @aNormalized, $sNormalized;
  }
  @aNormalized;  #return all normalized tokens
} @aUnNormalized;