A draft for term existence
diff --git a/lib/Krawfish/Result/Group/Segment/TermExistence.pm b/lib/Krawfish/Result/Group/Segment/TermExistence.pm
new file mode 100644
index 0000000..cf29935
--- /dev/null
+++ b/lib/Krawfish/Result/Group/Segment/TermExistence.pm
@@ -0,0 +1,159 @@
+package Krawfish::Result::Group::Segment::TermExistence;
+use parent 'Krawfish::Query';
+use strict;
+use warnings;
+
+# The query works similar to Or-query, but only accepts term ids.
+
+sub new {
+ my $class = shift;
+ bless {
+ term_id => shift, # Term Query
+ term_ids => shift, # Optional TermExistence-Query
+ filter => undef,
+ existence => []
+ }, $class;
+};
+
+sub _init {
+ ...
+};
+
+
+# TODO:
+# Think about when next() is called, as it needs to be called on term_ids as well ...
+# Mabe this should be done in _init as a while query somehow.
+sub next {
+ my $self = shift;
+
+ # Get the current document in the VC
+ my $filter = $self->{filter};
+ my $doc_id = $filter->doc_id;
+
+ # The next document to look for in the VC
+ my $next_doc_id;
+
+
+ # Check the single term_id for existence
+
+ # The simple term does not exist
+ my $term = $self->{term_id};
+ if (!$term) {
+ # Do nothing
+ }
+
+ # Should never happen
+ elsif (!$term->current) {
+ $self->{term_id} = undef;
+ }
+
+ # Term exists and can be checked
+ else {
+
+ # Is the VC document beyond the current document id
+ if ($doc_id > $term->doc_id) {
+
+ # Move the term document to the VC document
+ $term->skip_doc($doc_id);
+ };
+
+ # Are both terms in the same document?
+ if ($term->doc_id == $doc_id) {
+
+ # Add this term to existence
+ $self->exists($term->term_id);
+
+ # Close posting
+ $term->close;
+
+ # Do not check any further
+ $self->{term_id} = undef;
+ }
+
+ # Current term document is beyond current VC doc
+ else {
+ $next_doc_id = $term->doc_id;
+ };
+ };
+
+
+ # Check the complex term_ids for existence
+
+ my $terms = $self->{term_ids};
+
+ if (!$terms) {
+ # Do nothing
+ }
+
+ # Should never happen
+ elsif (!$terms->current) {
+ $self->{term_ids} = undef;
+ }
+
+ else {
+
+ # When there is a complex query, move on
+ if ($doc_id > $terms->doc_id) {
+ $terms->skip_doc($doc_id);
+ };
+
+ # There are no further matches
+ unless ($terms->current) {
+
+ # Merge existence values
+ $self->exists($terms->existence);
+ $terms->close;
+ $self->{term_ids} = undef;
+ }
+
+ # Current terms are beyond current VC doc
+ else {
+
+ # Remember the next relevant document id
+ if (!$next_doc_id || $next_doc_id > $term->doc_id) {
+ $next_doc_id = $term->doc_id;
+ };
+ };
+ };
+
+ # There is a next document id defined - move on
+ if (defined $next_doc_id) {
+
+ # Move the VC stream to the next relevant position
+ if ($filter->skip_doc($next_doc_id)) {
+
+ # It's fine
+ return 1;
+ };
+ };
+
+ return 0;
+};
+
+
+# Add term ids to existence list
+sub exists {
+ my ($self, $term_id) = @_;
+
+ if (ref $term_id) {
+ push @{$terms->existence}, @$term_id;
+ }
+ else {
+ push @{$terms->existence}, $term_id;
+ };
+};
+
+
+# Return list of existing term ids
+sub existence {
+ return $self->{existence}
+};
+
+
+sub filter_by {
+ ...
+ # It is relevant to filter The query - but one filter may be enough
+};
+
+
+1;