Subversion-Projekte lars-tiefland.prado

<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to version 1.0 of the Zend Framework

 * license, that is bundled with this package in the file LICENSE, and

 * is available through the world-wide-web at the following URL:

 * http://www.zend.com/license/framework/1_0.txt. If you did not receive

 * a copy of the Zend Framework license and are unable to obtain it

 * through the world-wide-web, please send a note to license@zend.com

 * so we can mail you a copy immediately.

 *

 * @package    Zend_Search_Lucene

 * @subpackage Search

 * @copyright  Copyright (c) 2005-2006 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://www.zend.com/license/framework/1_0.txt Zend Framework License version 1.0

 */

/** Zend_Search_Lucene_Search_QueryTokenizer */

require_once 'Zend/Search/Lucene/Search/QueryTokenizer.php';

/** Zend_Search_Lucene_Index_Term */

require_once 'Zend/Search/Lucene/Index/Term.php';

/** Zend_Search_Lucene_Search_Query_Term */

require_once 'Zend/Search/Lucene/Search/Query/Term.php';

/** Zend_Search_Lucene_Search_Query_MultiTerm */

require_once 'Zend/Search/Lucene/Search/Query/MultiTerm.php';

/** Zend_Search_Lucene_Search_Query_Phrase */

require_once 'Zend/Search/Lucene/Search/Query/Phrase.php';

/** Zend_Search_Lucene_Exception */

require_once 'Zend/Search/Lucene/Exception.php';

/**

 * @package    Zend_Search_Lucene

 * @subpackage Search

 * @copyright  Copyright (c) 2005-2006 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://www.zend.com/license/framework/1_0.txt Zend Framework License version 1.0

 */

class Zend_Search_Lucene_Search_QueryParser

{

    /**

     * Parses a query string, returning a Zend_Search_Lucene_Search_Query

     *

     * @param string $strQuery

     * @return Zend_Search_Lucene_Search_Query

     */

    static public function parse($strQuery)

    {

        $tokens = new Zend_Search_Lucene_Search_QueryTokenizer($strQuery);

        // Empty query

        if (!$tokens->count()) {

            throw new Zend_Search_Lucene_Exception('Syntax error: query string cannot be empty.');

        }

        // Term query

        if ($tokens->count() == 1) {

            if ($tokens->current()->type == Zend_Search_Lucene_Search_QueryToken::TOKTYPE_WORD) {

                return new Zend_Search_Lucene_Search_Query_Term(new Zend_Search_Lucene_Index_Term($tokens->current()->text, 'contents'));

            } else {

                throw new Zend_Search_Lucene_Exception('Syntax error: query string must contain at least one word.');

            }

        }

        /**

         * MultiTerm Query

         *

         * Process each token that was returned by the tokenizer.

         */

        $terms = array();

        $signs = array();

        $prevToken = null;

        $openBrackets = 0;

        $field = 'contents';

        foreach ($tokens as $token) {

            switch ($token->type) {

                case Zend_Search_Lucene_Search_QueryToken::TOKTYPE_WORD:

                    $terms[] = new Zend_Search_Lucene_Index_Term($token->text, $field);

                    $field = 'contents';

                    if ($prevToken !== null &&

                        $prevToken->type == Zend_Search_Lucene_Search_QueryToken::TOKTYPE_SIGN) {

                            if ($prevToken->text == "+") {

                                $signs[] = true;

                            } else {

                                $signs[] = false;

                            }

                    } else {

                        $signs[] = null;

                    }

                    break;

                case Zend_Search_Lucene_Search_QueryToken::TOKTYPE_SIGN:

                    if ($prevToken !== null &&

                        $prevToken->type == Zend_Search_Lucene_Search_QueryToken::TOKTYPE_SIGN) {

                            throw new Zend_Search_Lucene_Exception('Syntax error: sign operator must be followed by a word.');

                    }

                    break;

                case Zend_Search_Lucene_Search_QueryToken::TOKTYPE_FIELD:

                    $field = $token->text;

                    // let previous token to be signed as next $prevToken

                    $token = $prevToken;

                    break;

                case Zend_Search_Lucene_Search_QueryToken::TOKTYPE_BRACKET:

                    $token->text=='(' ? $openBrackets++ : $openBrackets--;

            }

            $prevToken = $token;

        }

        // Finish up parsing: check the last token in the query for an opening sign or parenthesis.

        if ($prevToken->type == Zend_Search_Lucene_Search_QueryToken::TOKTYPE_SIGN) {

            throw new Zend_Search_Lucene_Exception('Syntax Error: sign operator must be followed by a word.');

        }

        // Finish up parsing: check that every opening bracket has a matching closing bracket.

        if ($openBrackets != 0) {

            throw new Zend_Search_Lucene_Exception('Syntax Error: mismatched parentheses, every opening must have closing.');

        }

        switch (count($terms)) {

            case 0:

                throw new Zend_Search_Lucene_Exception('Syntax error: bad term count.');

            case 1:

                return new Zend_Search_Lucene_Search_Query_Term($terms[0],$signs[0] !== false);

            default:

                return new Zend_Search_Lucene_Search_Query_MultiTerm($terms,$signs);

        }

    }

}