wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch\Parser\AST;

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

/**
 * A boolean clause
 */
class BooleanClause implements Visitable {
    public const MUST = 'MUST';
    public const SHOULD = 'SHOULD';
    public const MUST_NOT = 'MUST_NOT';

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

    /**
     * Specifies how this clause is to occur in matching documents
     * @var string
     */
    private $occur;

    /**
     * @var bool true if the node is explicitly connected
     */
    private $explicit;

    private ?NegatedNode $negatedNode;

    /**
     * @param ParsedNode $node
     * @param string $occur Specifies how this clause is to occur in matching documents.
     * @param bool $explicit whether or not this node is explicitly connected
     * @param NegatedNode|null $negatedNode when in a MUST_NOT, remember how this clause was negated
     * acceptable values are BooleanClause::MUST, BooleanClause::MUST_NOT and BooleanClause::SHOULD
     */
    public function __construct( ParsedNode $node, $occur, $explicit, ?NegatedNode $negatedNode = null ) {
        $this->node = $node;
        $this->occur = $occur;
        self::validateOccur( $occur );
        Assert::parameter( ( $occur === self::MUST_NOT ) === ( $negatedNode !== null ), '$negatedNode',
            'A NegatedNode must be provided only if occur is MUST_NOT' );
        $this->explicit = $explicit;
        $this->negatedNode = $negatedNode;
    }

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

    /**
     * Check if $occur is valid
     * @param string $occur
     */
    public static function validateOccur( $occur ) {
        Assert::parameter( $occur === self::MUST || $occur === self::SHOULD || $occur === self::MUST_NOT,
            '$occur', 'must be either: MUST, SHOULD or MUST_NOT' );
    }

    /**
     * Specifies how this clause is to occur in matching documents
     * @return string
     */
    public function getOccur() {
        return $this->occur;
    }

    /**
     * @return bool
     */
    public function isExplicit() {
        return $this->explicit;
    }

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

    /**
     *
     * @return NegatedNode|null
     */
    public function getNegatedNode(): ?NegatedNode {
        return $this->negatedNode;
    }
}