1 files changed, 182 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/Query/Language/Conjunction.php b/www/wiki/extensions/SemanticMediaWiki/src/Query/Language/Conjunction.php
new file mode 100644
index 00000000..be5e8dbe
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+++ b/www/wiki/extensions/SemanticMediaWiki/src/Query/Language/Conjunction.php
@@ -0,0 +1,182 @@
+<?php
+
+namespace SMW\Query\Language;
+
+/**
+ * Description of a collection of many descriptions, all of which
+ * must be satisfied (AND, conjunction).
+ *
+ * Corresponds to conjunction in OWL and SPARQL. Not available in RDFS.
+ *
+ * @license GNU GPL v2+
+ * @since 1.6
+ *
+ * @author Markus Krötzsch
+ */
+class Conjunction extends Description {
+
+	/**
+	 * @var Description[]
+	 */
+	protected $descriptions = [];
+
+	/**
+	 * @since 1.6
+	 *
+	 * @param array $descriptions
+	 */
+	public function __construct( array $descriptions = [] ) {
+		foreach ( $descriptions as $description ) {
+			$this->addDescription( $description );
+		}
+	}
+
+	/**
+	 * @see Description::getFingerprint
+	 * @since 2.5
+	 *
+	 * @return string
+	 */
+	public function getFingerprint() {
+
+		if ( $this->fingerprint !== null ) {
+			return $this->fingerprint;
+		}
+
+		$fingerprint = [];
+
+		// Filter equal signatures
+		foreach ( $this->descriptions as $description ) {
+			$fingerprint[$description->getFingerprint()] = true;
+		}
+
+		// Sorting to generate a constant fingerprint independent of its
+		// position within a conjunction ( [Foo]][[Bar]], [[Bar]][[Foo]])
+		ksort( $fingerprint );
+
+		return $this->fingerprint = 'C:' . md5( implode( '|', array_keys( $fingerprint ) ) );
+	}
+
+	public function getDescriptions() {
+		return $this->descriptions;
+	}
+
+	public function addDescription( Description $description ) {
+
+		$this->fingerprint = null;
+
+		if ( ! ( $description instanceof ThingDescription ) ) {
+			if ( $description instanceof Conjunction ) { // absorb sub-conjunctions
+				foreach ( $description->getDescriptions() as $subdesc ) {
+					$this->descriptions[$subdesc->getFingerprint()] = $subdesc;
+				}
+			} else {
+				$this->descriptions[$description->getFingerprint()] = $description;
+			}
+
+			// move print descriptions downwards
+			///TODO: This may not be a good solution, since it does modify $description and since it does not react to future changes
+			$this->m_printreqs = array_merge( $this->m_printreqs, $description->getPrintRequests() );
+			$description->setPrintRequests( [] );
+		}
+
+		$fingerprint = $this->getFingerprint();
+
+		foreach ( $this->descriptions as $description ) {
+			$description->setMembership( $fingerprint );
+		}
+	}
+
+	public function getQueryString( $asvalue = false ) {
+		$result = '';
+
+		foreach ( $this->descriptions as $desc ) {
+			$result .= ( $result ? ' ' : '' ) . $desc->getQueryString( false );
+		}
+
+		if ( $result === '' ) {
+			return $asvalue ? '+' : '';
+		}
+
+		// <q> not needed for stand-alone conjunctions (AND binds stronger than OR)
+		return $asvalue ? " <q>{$result}</q> " : $result;
+	}
+
+	public function isSingleton() {
+		foreach ( $this->descriptions as $d ) {
+			if ( $d->isSingleton() ) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	public function getSize() {
+		$size = 0;
+
+		foreach ( $this->descriptions as $desc ) {
+			$size += $desc->getSize();
+		}
+
+		return $size;
+	}
+
+	public function getDepth() {
+		$depth = 0;
+
+		foreach ( $this->descriptions as $desc ) {
+			$depth = max( $depth, $desc->getDepth() );
+		}
+
+		return $depth;
+	}
+
+	public function getQueryFeatures() {
+		$result = SMW_CONJUNCTION_QUERY;
+
+		foreach ( $this->descriptions as $desc ) {
+			$result = $result | $desc->getQueryFeatures();
+		}
+
+		return $result;
+	}
+
+	public function prune( &$maxsize, &$maxdepth, &$log ) {
+		if ( $maxsize <= 0 ) {
+			$log[] = $this->getQueryString();
+			return new ThingDescription();
+		}
+
+		$prunelog = [];
+		$newdepth = $maxdepth;
+		$result = new Conjunction();
+
+		foreach ( $this->descriptions as $desc ) {
+			$restdepth = $maxdepth;
+			$result->addDescription( $desc->prune( $maxsize, $restdepth, $prunelog ) );
+			$newdepth = min( $newdepth, $restdepth );
+		}
+
+		if ( count( $result->getDescriptions() ) > 0 ) {
+			$log = array_merge( $log, $prunelog );
+			$maxdepth = $newdepth;
+
+			if ( count( $result->getDescriptions() ) == 1 ) { // simplify unary conjunctions!
+				$descriptions = $result->getDescriptions();
+				$result = array_shift( $descriptions );
+			}
+
+			$result->setPrintRequests( $this->getPrintRequests() );
+
+			return $result;
+		} else {
+			$log[] = $this->getQueryString();
+
+			$result = new ThingDescription();
+			$result->setPrintRequests( $this->getPrintRequests() );
+
+			return $result;
+		}
+	}
+
+}