wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch\Parser\AST;

use CirrusSearch\Parser\AST\Visitor\Visitor;
use Wikimedia\Assert\Assert;

/**
 * Negated node
 * NOTE: may not appear in any resulting query AST,
 * NegatedNode are always removed and attached to a BooleanClause
 * as MUST_NOT.
 */
class NegatedNode extends ParsedNode {

    /**
     * @var ParsedNode
     */
    private $child;

    /**
     * @var string type of negation used
     */
    private $negationType;

    /**
     * @param int $startOffset
     * @param int $endOffset
     * @param ParsedNode $child
     * @param string $negationType
     */
    public function __construct( $startOffset, $endOffset, ParsedNode $child, $negationType ) {
        Assert::parameter( self::validNegationType( $negationType ), 'negationType', 'Invalid negation type provided' );
        parent::__construct( $startOffset, $endOffset );
        $this->child = $child;
        $this->negationType = $negationType;
    }

    /**
     * @return array
     */
    public function toArray() {
        return [ 'not' => array_merge( parent::baseParams(), [
            'negation_type' => $this->negationType,
            'child' => $this->child->toArray(),
        ] ) ];
    }

    /**
     * @return ParsedNode
     */
    public function getChild() {
        return $this->child;
    }

    /**
     * Check whether this negation type is valid
     * @param string $negationType
     * @return bool
     */
    public static function validNegationType( $negationType ) {
        return $negationType === '!' || $negationType === '-' || $negationType === 'NOT';
    }

    /**
     * @return string type of negation used (NOT, ! or -)
     */
    public function getNegationType() {
        return $this->negationType;
    }

    /**
     * @param Visitor $visitor
     */
    public function accept( Visitor $visitor ) {
        $visitor->visitNegatedNode( $this );
    }
}