Re: Scalar data & collection data with Tree::Trie

[tangent]

failing to get a data retrieval in scalar context to function; it would always just return the word again.

I tried your code and using scalar context worked for me, i.e. it returned the data associated with the word, not the word itself.

use Tree::Trie;
my $trie = new Tree::Trie;
$trie->add_data( word => 'data');
my @sent = $trie->lookup_data('word');
print "List context: @sent\n";
my $data = $trie->lookup_data('word');
print "Scalar context: $data\n";

Output:

List context: word data
Scalar context: data

Maybe you could post up some of your input file? It would help to answer your second question as well.

Update: Is it possible you are using "scalar context" like this:

my ($data) = $trie->lookup_data($fields->[0]);

If so, that will indeed return the word and not the data, you need to leave out the brackets around $data

[Endless]

Thanks! You are exactly right about why my scalar wasn't working; I was calling it as 'my ($var).' Can you give me a quick line on why I should/shouldn't have the parenthesis on that?

I seem to have the multi-data working now, and I'll show you what I did. I suspect it is pretty sloppy, un-idiomatic code, so any suggestions for a cleaner implementation are welcome. Here we are. First, my CSV format (for reference):

"PrimaryTest","normalSentiment","negSentiment","topics"
"a waste",-1,0,""

Now my code:

while (my $fields = $csv->getline( $data )) {
    my $word = $fields -> [0];
    my $pos_sent = $fields->[1];
    my $neg_sent = $fields->[2];
    my $topics = $fields->[3];
    my @word_info = ($pos_sent, $neg_sent, $topics);

    # Trying with a reference
    my $pnt_word_info = \@word_info;
    $trie->add_data($word => $pnt_word_info);

    my $info = $trie->lookup_data($word);
    printf "Just added %s\n Sentiment: %s \t Neg Sentiment: %s \t Topi
+c: %s\n", $word, $info->[0], $info->[1], $info->[2];
}

[tangent]

my ($var) is imposing list context, $var will contain the first element of the list returned (in this case the word).

With regards to your code there's nothing really wrong with it but, unless you need the intermediate variables for something else, it could be shortened to:

while (my $fields = $csv->getline( $data )) {
    my $word = $fields->[0];
    $trie->add_data( $word => [ $fields->[1], $fields->[2], $fields->[
+3] ] );

    my $info = $trie->lookup_data($word);
    printf "Just added %s\n Sentiment: %s \t Neg Sentiment: %s \t Topi
+c: %s\n", $word, $info->[0], $info->[1], $info->[2];
}