QueryLexer.php 24.5 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508
<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Search_Lucene
 * @subpackage Search
 * @copyright  Copyright (c) 2005-2007 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */


/** Zend_Search_Lucene_FSM */
require_once 'Zend/Search/Lucene/FSM.php';

/** Zend_Search_Lucene_Search_QueryParser */
require_once 'Zend/Search/Lucene/Search/QueryToken.php';

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

/** Zend_Search_Lucene_Search_QueryParserException */
require_once 'Zend/Search/Lucene/Search/QueryParserException.php';


/**
 * @category   Zend
 * @package    Zend_Search_Lucene
 * @subpackage Search
 * @copyright  Copyright (c) 2005-2007 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Search_Lucene_Search_QueryLexer extends Zend_Search_Lucene_FSM
{
    /** State Machine states */
    const ST_WHITE_SPACE     = 0;
    const ST_SYNT_LEXEME     = 1;
    const ST_LEXEME          = 2;
    const ST_QUOTED_LEXEME   = 3;
    const ST_ESCAPED_CHAR    = 4;
    const ST_ESCAPED_QCHAR   = 5;
    const ST_LEXEME_MODIFIER = 6;
    const ST_NUMBER          = 7;
    const ST_MANTISSA        = 8;
    const ST_ERROR           = 9;

    /** Input symbols */
    const IN_WHITE_SPACE     = 0;
    const IN_SYNT_CHAR       = 1;
    const IN_LEXEME_MODIFIER = 2;
    const IN_ESCAPE_CHAR     = 3;
    const IN_QUOTE           = 4;
    const IN_DECIMAL_POINT   = 5;
    const IN_ASCII_DIGIT     = 6;
    const IN_CHAR            = 7;
    const IN_MUTABLE_CHAR    = 8;

    const QUERY_WHITE_SPACE_CHARS      = " \n\r\t";
    const QUERY_SYNT_CHARS             = ':()[]{}!|&';
    const QUERY_MUTABLE_CHARS          = '+-';
    const QUERY_DOUBLECHARLEXEME_CHARS = '|&';
    const QUERY_LEXEMEMODIFIER_CHARS   = '~^';
    const QUERY_ASCIIDIGITS_CHARS      = '0123456789';

    /**
     * List of recognized lexemes
     *
     * @var array
     */
    private $_lexemes;

    /**
     * Query string (array of single- or non single-byte characters)
     *
     * @var array
     */
    private $_queryString;

    /**
     * Current position within a query string
     * Used to create appropriate error messages
     *
     * @var integer
     */
    private $_queryStringPosition;

    /**
     * Recognized part of current lexeme
     *
     * @var string
     */
    private $_currentLexeme;

    public function __construct()
    {
        parent::__construct( array(self::ST_WHITE_SPACE,
                                   self::ST_SYNT_LEXEME,
                                   self::ST_LEXEME,
                                   self::ST_QUOTED_LEXEME,
                                   self::ST_ESCAPED_CHAR,
                                   self::ST_ESCAPED_QCHAR,
                                   self::ST_LEXEME_MODIFIER,
                                   self::ST_NUMBER,
                                   self::ST_MANTISSA,
                                   self::ST_ERROR),
                             array(self::IN_WHITE_SPACE,
                                   self::IN_SYNT_CHAR,
                                   self::IN_MUTABLE_CHAR,
                                   self::IN_LEXEME_MODIFIER,
                                   self::IN_ESCAPE_CHAR,
                                   self::IN_QUOTE,
                                   self::IN_DECIMAL_POINT,
                                   self::IN_ASCII_DIGIT,
                                   self::IN_CHAR));


        $lexemeModifierErrorAction    = new Zend_Search_Lucene_FSMAction($this, 'lexModifierErrException');
        $quoteWithinLexemeErrorAction = new Zend_Search_Lucene_FSMAction($this, 'quoteWithinLexemeErrException');
        $wrongNumberErrorAction       = new Zend_Search_Lucene_FSMAction($this, 'wrongNumberErrException');



        $this->addRules(array( array(self::ST_WHITE_SPACE,   self::IN_WHITE_SPACE,     self::ST_WHITE_SPACE),
                               array(self::ST_WHITE_SPACE,   self::IN_SYNT_CHAR,       self::ST_SYNT_LEXEME),
                               array(self::ST_WHITE_SPACE,   self::IN_MUTABLE_CHAR,    self::ST_SYNT_LEXEME),
                               array(self::ST_WHITE_SPACE,   self::IN_LEXEME_MODIFIER, self::ST_LEXEME_MODIFIER),
                               array(self::ST_WHITE_SPACE,   self::IN_ESCAPE_CHAR,     self::ST_ESCAPED_CHAR),
                               array(self::ST_WHITE_SPACE,   self::IN_QUOTE,           self::ST_QUOTED_LEXEME),
                               array(self::ST_WHITE_SPACE,   self::IN_DECIMAL_POINT,   self::ST_LEXEME),
                               array(self::ST_WHITE_SPACE,   self::IN_ASCII_DIGIT,     self::ST_LEXEME),
                               array(self::ST_WHITE_SPACE,   self::IN_CHAR,            self::ST_LEXEME)
                             ));
        $this->addRules(array( array(self::ST_SYNT_LEXEME,   self::IN_WHITE_SPACE,     self::ST_WHITE_SPACE),
                               array(self::ST_SYNT_LEXEME,   self::IN_SYNT_CHAR,       self::ST_SYNT_LEXEME),
                               array(self::ST_SYNT_LEXEME,   self::IN_MUTABLE_CHAR,    self::ST_SYNT_LEXEME),
                               array(self::ST_SYNT_LEXEME,   self::IN_LEXEME_MODIFIER, self::ST_LEXEME_MODIFIER),
                               array(self::ST_SYNT_LEXEME,   self::IN_ESCAPE_CHAR,     self::ST_ESCAPED_CHAR),
                               array(self::ST_SYNT_LEXEME,   self::IN_QUOTE,           self::ST_QUOTED_LEXEME),
                               array(self::ST_SYNT_LEXEME,   self::IN_DECIMAL_POINT,   self::ST_LEXEME),
                               array(self::ST_SYNT_LEXEME,   self::IN_ASCII_DIGIT,     self::ST_LEXEME),
                               array(self::ST_SYNT_LEXEME,   self::IN_CHAR,            self::ST_LEXEME)
                             ));
        $this->addRules(array( array(self::ST_LEXEME,        self::IN_WHITE_SPACE,     self::ST_WHITE_SPACE),
                               array(self::ST_LEXEME,        self::IN_SYNT_CHAR,       self::ST_SYNT_LEXEME),
                               array(self::ST_LEXEME,        self::IN_MUTABLE_CHAR,    self::ST_LEXEME),
                               array(self::ST_LEXEME,        self::IN_LEXEME_MODIFIER, self::ST_LEXEME_MODIFIER),
                               array(self::ST_LEXEME,        self::IN_ESCAPE_CHAR,     self::ST_ESCAPED_CHAR),

                               // IN_QUOTE     not allowed
                               array(self::ST_LEXEME,        self::IN_QUOTE,           self::ST_ERROR, $quoteWithinLexemeErrorAction),

                               array(self::ST_LEXEME,        self::IN_DECIMAL_POINT,   self::ST_LEXEME),
                               array(self::ST_LEXEME,        self::IN_ASCII_DIGIT,     self::ST_LEXEME),
                               array(self::ST_LEXEME,        self::IN_CHAR,            self::ST_LEXEME)
                             ));
        $this->addRules(array( array(self::ST_QUOTED_LEXEME, self::IN_WHITE_SPACE,     self::ST_QUOTED_LEXEME),
                               array(self::ST_QUOTED_LEXEME, self::IN_SYNT_CHAR,       self::ST_QUOTED_LEXEME),
                               array(self::ST_QUOTED_LEXEME, self::IN_MUTABLE_CHAR,    self::ST_QUOTED_LEXEME),
                               array(self::ST_QUOTED_LEXEME, self::IN_LEXEME_MODIFIER, self::ST_QUOTED_LEXEME),
                               array(self::ST_QUOTED_LEXEME, self::IN_ESCAPE_CHAR,     self::ST_ESCAPED_QCHAR),
                               array(self::ST_QUOTED_LEXEME, self::IN_QUOTE,           self::ST_WHITE_SPACE),
                               array(self::ST_QUOTED_LEXEME, self::IN_DECIMAL_POINT,   self::ST_QUOTED_LEXEME),
                               array(self::ST_QUOTED_LEXEME, self::IN_ASCII_DIGIT,     self::ST_QUOTED_LEXEME),
                               array(self::ST_QUOTED_LEXEME, self::IN_CHAR,            self::ST_QUOTED_LEXEME)
                             ));
        $this->addRules(array( array(self::ST_ESCAPED_CHAR,  self::IN_WHITE_SPACE,     self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_SYNT_CHAR,       self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_MUTABLE_CHAR,    self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_LEXEME_MODIFIER, self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_ESCAPE_CHAR,     self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_QUOTE,           self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_DECIMAL_POINT,   self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_ASCII_DIGIT,     self::ST_LEXEME),
                               array(self::ST_ESCAPED_CHAR,  self::IN_CHAR,            self::ST_LEXEME)
                             ));
        $this->addRules(array( array(self::ST_ESCAPED_QCHAR, self::IN_WHITE_SPACE,     self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_SYNT_CHAR,       self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_MUTABLE_CHAR,    self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_LEXEME_MODIFIER, self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_ESCAPE_CHAR,     self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_QUOTE,           self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_DECIMAL_POINT,   self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_ASCII_DIGIT,     self::ST_QUOTED_LEXEME),
                               array(self::ST_ESCAPED_QCHAR, self::IN_CHAR,            self::ST_QUOTED_LEXEME)
                             ));
        $this->addRules(array( array(self::ST_LEXEME_MODIFIER, self::IN_WHITE_SPACE,     self::ST_WHITE_SPACE),
                               array(self::ST_LEXEME_MODIFIER, self::IN_SYNT_CHAR,       self::ST_SYNT_LEXEME),
                               array(self::ST_LEXEME_MODIFIER, self::IN_MUTABLE_CHAR,    self::ST_SYNT_LEXEME),
                               array(self::ST_LEXEME_MODIFIER, self::IN_LEXEME_MODIFIER, self::ST_LEXEME_MODIFIER),

                               // IN_ESCAPE_CHAR       not allowed
                               array(self::ST_LEXEME_MODIFIER, self::IN_ESCAPE_CHAR,     self::ST_ERROR, $lexemeModifierErrorAction),

                               // IN_QUOTE             not allowed
                               array(self::ST_LEXEME_MODIFIER, self::IN_QUOTE,           self::ST_ERROR, $lexemeModifierErrorAction),


                               array(self::ST_LEXEME_MODIFIER, self::IN_DECIMAL_POINT,   self::ST_MANTISSA),
                               array(self::ST_LEXEME_MODIFIER, self::IN_ASCII_DIGIT,     self::ST_NUMBER),

                               // IN_CHAR              not allowed
                               array(self::ST_LEXEME_MODIFIER, self::IN_CHAR,            self::ST_ERROR, $lexemeModifierErrorAction),
                             ));
        $this->addRules(array( array(self::ST_NUMBER, self::IN_WHITE_SPACE,     self::ST_WHITE_SPACE),
                               array(self::ST_NUMBER, self::IN_SYNT_CHAR,       self::ST_SYNT_LEXEME),
                               array(self::ST_NUMBER, self::IN_MUTABLE_CHAR,    self::ST_SYNT_LEXEME),
                               array(self::ST_NUMBER, self::IN_LEXEME_MODIFIER, self::ST_LEXEME_MODIFIER),

                               // IN_ESCAPE_CHAR       not allowed
                               array(self::ST_NUMBER, self::IN_ESCAPE_CHAR,     self::ST_ERROR, $wrongNumberErrorAction),

                               // IN_QUOTE             not allowed
                               array(self::ST_NUMBER, self::IN_QUOTE,           self::ST_ERROR, $wrongNumberErrorAction),

                               array(self::ST_NUMBER, self::IN_DECIMAL_POINT,   self::ST_MANTISSA),
                               array(self::ST_NUMBER, self::IN_ASCII_DIGIT,     self::ST_NUMBER),

                               // IN_CHAR              not allowed
                               array(self::ST_NUMBER, self::IN_CHAR,            self::ST_ERROR, $wrongNumberErrorAction),
                             ));
        $this->addRules(array( array(self::ST_MANTISSA, self::IN_WHITE_SPACE,     self::ST_WHITE_SPACE),
                               array(self::ST_MANTISSA, self::IN_SYNT_CHAR,       self::ST_SYNT_LEXEME),
                               array(self::ST_MANTISSA, self::IN_MUTABLE_CHAR,    self::ST_SYNT_LEXEME),
                               array(self::ST_MANTISSA, self::IN_LEXEME_MODIFIER, self::ST_LEXEME_MODIFIER),

                               // IN_ESCAPE_CHAR       not allowed
                               array(self::ST_MANTISSA, self::IN_ESCAPE_CHAR,     self::ST_ERROR, $wrongNumberErrorAction),

                               // IN_QUOTE             not allowed
                               array(self::ST_MANTISSA, self::IN_QUOTE,           self::ST_ERROR, $wrongNumberErrorAction),

                               // IN_DECIMAL_POINT     not allowed
                               array(self::ST_MANTISSA, self::IN_DECIMAL_POINT,   self::ST_ERROR, $wrongNumberErrorAction),

                               array(self::ST_MANTISSA, self::IN_ASCII_DIGIT,     self::ST_MANTISSA),

                               // IN_CHAR              not allowed
                               array(self::ST_MANTISSA, self::IN_CHAR,            self::ST_ERROR, $wrongNumberErrorAction),
                             ));


        /** Actions */
        $syntaxLexemeAction    = new Zend_Search_Lucene_FSMAction($this, 'addQuerySyntaxLexeme');
        $lexemeModifierAction  = new Zend_Search_Lucene_FSMAction($this, 'addLexemeModifier');
        $addLexemeAction       = new Zend_Search_Lucene_FSMAction($this, 'addLexeme');
        $addQuotedLexemeAction = new Zend_Search_Lucene_FSMAction($this, 'addQuotedLexeme');
        $addNumberLexemeAction = new Zend_Search_Lucene_FSMAction($this, 'addNumberLexeme');
        $addLexemeCharAction   = new Zend_Search_Lucene_FSMAction($this, 'addLexemeChar');


        /** Syntax lexeme */
        $this->addEntryAction(self::ST_SYNT_LEXEME,  $syntaxLexemeAction);
        // Two lexemes in succession
        $this->addTransitionAction(self::ST_SYNT_LEXEME, self::ST_SYNT_LEXEME, $syntaxLexemeAction);


        /** Lexeme */
        $this->addEntryAction(self::ST_LEXEME,                       $addLexemeCharAction);
        $this->addTransitionAction(self::ST_LEXEME, self::ST_LEXEME, $addLexemeCharAction);
        // ST_ESCAPED_CHAR => ST_LEXEME transition is covered by ST_LEXEME entry action

        $this->addTransitionAction(self::ST_LEXEME, self::ST_WHITE_SPACE,     $addLexemeAction);
        $this->addTransitionAction(self::ST_LEXEME, self::ST_SYNT_LEXEME,     $addLexemeAction);
        $this->addTransitionAction(self::ST_LEXEME, self::ST_QUOTED_LEXEME,   $addLexemeAction);
        $this->addTransitionAction(self::ST_LEXEME, self::ST_LEXEME_MODIFIER, $addLexemeAction);
        $this->addTransitionAction(self::ST_LEXEME, self::ST_NUMBER,          $addLexemeAction);
        $this->addTransitionAction(self::ST_LEXEME, self::ST_MANTISSA,        $addLexemeAction);


        /** Quoted lexeme */
        // We don't need entry action (skeep quote)
        $this->addTransitionAction(self::ST_QUOTED_LEXEME, self::ST_QUOTED_LEXEME, $addLexemeCharAction);
        $this->addTransitionAction(self::ST_ESCAPED_QCHAR, self::ST_QUOTED_LEXEME, $addLexemeCharAction);
        // Closing quote changes state to the ST_WHITE_SPACE   other states are not used
        $this->addTransitionAction(self::ST_QUOTED_LEXEME, self::ST_WHITE_SPACE,   $addQuotedLexemeAction);


        /** Lexeme modifier */
        $this->addEntryAction(self::ST_LEXEME_MODIFIER, $lexemeModifierAction);


        /** Number */
        $this->addEntryAction(self::ST_NUMBER,                           $addLexemeCharAction);
        $this->addEntryAction(self::ST_MANTISSA,                         $addLexemeCharAction);
        $this->addTransitionAction(self::ST_NUMBER,   self::ST_NUMBER,   $addLexemeCharAction);
        // ST_NUMBER => ST_MANTISSA transition is covered by ST_MANTISSA entry action
        $this->addTransitionAction(self::ST_MANTISSA, self::ST_MANTISSA, $addLexemeCharAction);

        $this->addTransitionAction(self::ST_NUMBER,   self::ST_WHITE_SPACE,     $addNumberLexemeAction);
        $this->addTransitionAction(self::ST_NUMBER,   self::ST_SYNT_LEXEME,     $addNumberLexemeAction);
        $this->addTransitionAction(self::ST_NUMBER,   self::ST_LEXEME_MODIFIER, $addNumberLexemeAction);
        $this->addTransitionAction(self::ST_MANTISSA, self::ST_WHITE_SPACE,     $addNumberLexemeAction);
        $this->addTransitionAction(self::ST_MANTISSA, self::ST_SYNT_LEXEME,     $addNumberLexemeAction);
        $this->addTransitionAction(self::ST_MANTISSA, self::ST_LEXEME_MODIFIER, $addNumberLexemeAction);
    }




    /**
     * Translate input char to an input symbol of state machine
     *
     * @param string $char
     * @return integer
     */
    private function _translateInput($char)
    {
        if        (strpos(self::QUERY_WHITE_SPACE_CHARS,    $char) !== false) { return self::IN_WHITE_SPACE;
        } else if (strpos(self::QUERY_SYNT_CHARS,           $char) !== false) { return self::IN_SYNT_CHAR;
        } else if (strpos(self::QUERY_MUTABLE_CHARS,        $char) !== false) { return self::IN_MUTABLE_CHAR;
        } else if (strpos(self::QUERY_LEXEMEMODIFIER_CHARS, $char) !== false) { return self::IN_LEXEME_MODIFIER;
        } else if (strpos(self::QUERY_ASCIIDIGITS_CHARS,    $char) !== false) { return self::IN_ASCII_DIGIT;
        } else if ($char === '"' )                                            { return self::IN_QUOTE;
        } else if ($char === '.' )                                            { return self::IN_DECIMAL_POINT;
        } else if ($char === '\\')                                            { return self::IN_ESCAPE_CHAR;
        } else                                                                { return self::IN_CHAR;
        }
    }


    /**
     * This method is used to tokenize query string into lexemes
     *
     * @param string $inputString
     * @param string $encoding
     * @return array
     * @throws Zend_Search_Lucene_Search_QueryParserException
     */
    public function tokenize($inputString, $encoding)
    {
        $this->reset();

        $this->_lexemes     = array();
        $this->_queryString = array();

        $strLength = iconv_strlen($inputString, $encoding);

        // Workaround for iconv_substr bug
        $inputString .= ' ';

        for ($count = 0; $count < $strLength; $count++) {
            $this->_queryString[$count] = iconv_substr($inputString, $count, 1, $encoding);
        }

        for ($this->_queryStringPosition = 0;
             $this->_queryStringPosition < count($this->_queryString);
             $this->_queryStringPosition++) {
            $this->process($this->_translateInput($this->_queryString[$this->_queryStringPosition]));
        }

        $this->process(self::IN_WHITE_SPACE);

        if ($this->getState() != self::ST_WHITE_SPACE) {
            throw new Zend_Search_Lucene_Search_QueryParserException('Unexpected end of query');
        }

        $this->_queryString = null;

        return $this->_lexemes;
    }



    /*********************************************************************
     * Actions implementation
     *
     * Actions affect on recognized lexemes list
     *********************************************************************/

    /**
     * Add query syntax lexeme
     *
     * @throws Zend_Search_Lucene_Search_QueryParserException
     */
    public function addQuerySyntaxLexeme()
    {
        $lexeme = $this->_queryString[$this->_queryStringPosition];

        // Process two char lexemes
        if (strpos(self::QUERY_DOUBLECHARLEXEME_CHARS, $lexeme) !== false) {
            // increase current position in a query string
            $this->_queryStringPosition++;

            // check,
            if ($this->_queryStringPosition == count($this->_queryString)  ||
                $this->_queryString[$this->_queryStringPosition] != $lexeme) {
                    throw new Zend_Search_Lucene_Search_QueryParserException('Two chars lexeme expected. ' . $this->_positionMsg());
                }

            // duplicate character
            $lexeme .= $lexeme;
        }

        $token = new Zend_Search_Lucene_Search_QueryToken(
                                Zend_Search_Lucene_Search_QueryToken::TC_SYNTAX_ELEMENT,
                                $lexeme,
                                $this->_queryStringPosition);

        // Skip this lexeme if it's a field indicator ':' and treat previous as 'field' instead of 'word'
        if ($token->type == Zend_Search_Lucene_Search_QueryToken::TT_FIELD_INDICATOR) {
            $token = array_pop($this->_lexemes);
            if ($token === null  ||  $token->type != Zend_Search_Lucene_Search_QueryToken::TT_WORD) {
                throw new Zend_Search_Lucene_Search_QueryParserException('Field mark \':\' must follow field name. ' . $this->_positionMsg());
            }

            $token->type = Zend_Search_Lucene_Search_QueryToken::TT_FIELD;
        }

        $this->_lexemes[] = $token;
    }

    /**
     * Add lexeme modifier
     */
    public function addLexemeModifier()
    {
        $this->_lexemes[] = new Zend_Search_Lucene_Search_QueryToken(
                                    Zend_Search_Lucene_Search_QueryToken::TC_SYNTAX_ELEMENT,
                                    $this->_queryString[$this->_queryStringPosition],
                                    $this->_queryStringPosition);
    }


    /**
     * Add lexeme
     */
    public function addLexeme()
    {
        $this->_lexemes[] = new Zend_Search_Lucene_Search_QueryToken(
                                    Zend_Search_Lucene_Search_QueryToken::TC_WORD,
                                    $this->_currentLexeme,
                                    $this->_queryStringPosition - 1);

        $this->_currentLexeme = '';
    }

    /**
     * Add quoted lexeme
     */
    public function addQuotedLexeme()
    {
        $this->_lexemes[] = new Zend_Search_Lucene_Search_QueryToken(
                                    Zend_Search_Lucene_Search_QueryToken::TC_PHRASE,
                                    $this->_currentLexeme,
                                    $this->_queryStringPosition);

        $this->_currentLexeme = '';
    }

    /**
     * Add number lexeme
     */
    public function addNumberLexeme()
    {
        $this->_lexemes[] = new Zend_Search_Lucene_Search_QueryToken(
                                    Zend_Search_Lucene_Search_QueryToken::TC_NUMBER,
                                    $this->_currentLexeme,
                                    $this->_queryStringPosition - 1);
        $this->_currentLexeme = '';
    }

    /**
     * Extend lexeme by one char
     */
    public function addLexemeChar()
    {
        $this->_currentLexeme .= $this->_queryString[$this->_queryStringPosition];
    }


    /**
     * Position message
     *
     * @return string
     */
    private function _positionMsg()
    {
        return 'Position is ' . $this->_queryStringPosition . '.';
    }


    /*********************************************************************
     * Syntax errors actions
     *********************************************************************/
    public function lexModifierErrException()
    {
        throw new Zend_Search_Lucene_Search_QueryParserException('Lexeme modifier character can be followed only by number, white space or query syntax element. ' . $this->_positionMsg());
    }
    public function quoteWithinLexemeErrException()
    {
        throw new Zend_Search_Lucene_Search_QueryParserException('Quote within lexeme must be escaped by \'\\\' char. ' . $this->_positionMsg());
    }
    public function wrongNumberErrException()
    {
        throw new Zend_Search_Lucene_Search_QueryParserException('Wrong number syntax.' . $this->_positionMsg());
    }
}