my @words_stemmed = @words;
$stemmer->stem_in_place(\@words_stemmed);
my @all; # will contain hashrefs like { original => 'books' , stemmed => 'book' }
map{
   +{
     original => $words[$_],
     stemmed  => $words_stemmed[$_],
   };
} 0..-1+@words;