searchcommandparser.php

PHP 知识管理系统（基于树结构的知识管理系统）, 英文原版的PHP源码。

    const YYERRORSYMBOL = 26;
    const YYERRSYMDT = 'yy0';
    const YYFALLBACK = 0;
    /** The next table maps tokens into fallback tokens.  If a construct
     * like the following:
     * 
     *      %fallback ID X Y Z.
     *
     * appears in the grammer, then ID becomes a fallback token for X, Y,
     * and Z.  Whenever one of the tokens X, Y, or Z is input to the parser
     * but it does not parse, the type of the token is changed to ID and
     * the parse is retried before an error is thrown.
     */
    static public $yyFallback = array(
    );
    /**
     * Turn parser tracing on by giving a stream to which to write the trace
     * and a prompt to preface each trace message.  Tracing is turned off
     * by making either argument NULL 
     *
     * Inputs:
     * 
     * - A stream resource to which trace output should be written.
     *   If NULL, then tracing is turned off.
     * - A prefix string written at the beginning of every
     *   line of trace output.  If NULL, then tracing is
     *   turned off.
     *
     * Outputs:
     * 
     * - None.
     * @param resource
     * @param string
     */
    static function Trace($TraceFILE, $zTracePrompt)
    {
        if (!$TraceFILE) {
            $zTracePrompt = 0;
        } elseif (!$zTracePrompt) {
            $TraceFILE = 0;
        }
        self::$yyTraceFILE = $TraceFILE;
        self::$yyTracePrompt = $zTracePrompt;
    }

    /**
     * Output debug information to output (php://output stream)
     */
    static function PrintTrace()
    {
        self::$yyTraceFILE = fopen('php://output', 'w');
        self::$yyTracePrompt = '';
    }

    /**
     * @var resource|0
     */
    static public $yyTraceFILE;
    /**
     * String to prepend to debug output
     * @var string|0
     */
    static public $yyTracePrompt;
    /**
     * @var int
     */
    public $yyidx;                    /* Index of top element in stack */
    /**
     * @var int
     */
    public $yyerrcnt;                 /* Shifts left before out of the error */
    /**
     * @var array
     */
    public $yystack = array();  /* The parser's stack */

    /**
     * For tracing shifts, the names of all terminals and nonterminals
     * are required.  The following table supplies these names
     * @var array
     */
    static public $yyTokenName = array( 
  '$',             'OPOR',          'OPAND',         'NOT',         
  'IS',            'CONTAIN',       'LIKE',          'BETWEEN',     
  'START',         'END',           'GT',            'LE',          
  'LT',            'GE',            'PAR_OPEN',      'PAR_CLOSE',   
  'DOES',          'CONTAINS',      'COLON',         'SQUARE_OPEN', 
  'SQUARE_CLOSE',  'TERMINAL',      'VALUE',         'COMMA',       
  'WITH',          'IS_NOT',        'error',         'expr',        
  'cmdline',       'terminal',      'operator',      'value',       
  'notop',         'valuelist',   
    );

    /**
     * For tracing reduce actions, the names of all rules are required.
     * @var array
     */
    static public $yyRuleName = array(
 /*   0 */ "cmdline ::= expr",
 /*   1 */ "expr ::= expr OPAND expr",
 /*   2 */ "expr ::= expr OPOR expr",
 /*   3 */ "expr ::= NOT expr",
 /*   4 */ "expr ::= PAR_OPEN expr PAR_CLOSE",
 /*   5 */ "expr ::= terminal operator value",
 /*   6 */ "expr ::= terminal notop BETWEEN value OPAND value",
 /*   7 */ "expr ::= terminal notop LIKE value",
 /*   8 */ "expr ::= terminal IS notop value",
 /*   9 */ "expr ::= terminal DOES notop CONTAINS value",
 /*  10 */ "expr ::= terminal COLON value",
 /*  11 */ "notop ::=",
 /*  12 */ "notop ::= NOT",
 /*  13 */ "terminal ::= SQUARE_OPEN value SQUARE_CLOSE SQUARE_OPEN value SQUARE_CLOSE",
 /*  14 */ "terminal ::= TERMINAL",
 /*  15 */ "value ::= VALUE",
 /*  16 */ "value ::= PAR_OPEN valuelist PAR_CLOSE",
 /*  17 */ "valuelist ::= VALUE COMMA valuelist",
 /*  18 */ "valuelist ::= VALUE",
 /*  19 */ "operator ::= CONTAINS",
 /*  20 */ "operator ::= LT",
 /*  21 */ "operator ::= GT",
 /*  22 */ "operator ::= LE",
 /*  23 */ "operator ::= GE",
 /*  24 */ "operator ::= START WITH",
 /*  25 */ "operator ::= END WITH",
 /*  26 */ "operator ::= IS_NOT",
    );

    /**
     * This function returns the symbolic name associated with a token
     * value.
     * @param int
     * @return string
     */
    function tokenName($tokenType)
    {
        if ($tokenType === 0) {
            return 'End of Input';
        }
        if ($tokenType > 0 && $tokenType < count(self::$yyTokenName)) {
            return self::$yyTokenName[$tokenType];
        } else {
            return "Unknown";
        }
    }

    /**
     * The following function deletes the value associated with a
     * symbol.  The symbol can be either a terminal or nonterminal.
     * @param int the symbol code
     * @param mixed the symbol's value
     */
    static function yy_destructor($yymajor, $yypminor)
    {
        switch ($yymajor) {
        /* Here is inserted the actions which take place when a
        ** terminal or non-terminal is destroyed.  This can happen
        ** when the symbol is popped from the stack during a
        ** reduce or during error processing or when a parser is 
        ** being destroyed before it is finished parsing.
        **
        ** Note: during a reduce, the only symbols destroyed are those
        ** which appear on the RHS of the rule, but which are not used
        ** inside the C code.
        */
            default:  break;   /* If no destructor action specified: do nothing */
        }
    }

    /**
     * Pop the parser's stack once.
     *
     * If there is a destructor routine associated with the token which
     * is popped from the stack, then call it.
     *
     * Return the major token number for the symbol popped.
     * @param SearchCommandParseryyParser
     * @return int
     */
    function yy_pop_parser_stack()
    {
        if (!count($this->yystack)) {
            return;
        }
        $yytos = array_pop($this->yystack);
        if (self::$yyTraceFILE && $this->yyidx >= 0) {
            fwrite(self::$yyTraceFILE,
                self::$yyTracePrompt . 'Popping ' . self::$yyTokenName[$yytos->major] .
                    "\n");
        }
        $yymajor = $yytos->major;
        self::yy_destructor($yymajor, $yytos->minor);
        $this->yyidx--;
        return $yymajor;
    }

    /**
     * Deallocate and destroy a parser.  Destructors are all called for
     * all stack elements before shutting the parser down.
     */
    function __destruct()
    {
        while ($this->yyidx >= 0) {
            $this->yy_pop_parser_stack();
        }
        if (is_resource(self::$yyTraceFILE)) {
            fclose(self::$yyTraceFILE);
        }
    }

    /**
     * Based on the current state and parser stack, get a list of all
     * possible lookahead tokens
     * @param int
     * @return array
     */
    function yy_get_expected_tokens($token)
    {
        $state = $this->yystack[$this->yyidx]->stateno;
        $expected = self::$yyExpectedTokens[$state];
        if (in_array($token, self::$yyExpectedTokens[$state], true)) {
            return $expected;
        }
        $stack = $this->yystack;
        $yyidx = $this->yyidx;
        do {
            $yyact = $this->yy_find_shift_action($token);
            if ($yyact >= self::YYNSTATE && $yyact < self::YYNSTATE + self::YYNRULE) {
                // reduce action
                $done = 0;
                do {
                    if ($done++ == 100) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        // too much recursion prevents proper detection
                        // so give up
                        return array_unique($expected);
                    }
                    $yyruleno = $yyact - self::YYNSTATE;
                    $this->yyidx -= self::$yyRuleInfo[$yyruleno]['rhs'];
                    $nextstate = $this->yy_find_reduce_action(
                        $this->yystack[$this->yyidx]->stateno,
                        self::$yyRuleInfo[$yyruleno]['lhs']);
                    if (isset(self::$yyExpectedTokens[$nextstate])) {
                        $expected += self::$yyExpectedTokens[$nextstate];
                            if (in_array($token,
                                  self::$yyExpectedTokens[$nextstate], true)) {
                            $this->yyidx = $yyidx;
                            $this->yystack = $stack;
                            return array_unique($expected);
                        }
                    }
                    if ($nextstate < self::YYNSTATE) {
                        // we need to shift a non-terminal
                        $this->yyidx++;
                        $x = new SearchCommandParseryyStackEntry;
                        $x->stateno = $nextstate;
                        $x->major = self::$yyRuleInfo[$yyruleno]['lhs'];
                        $this->yystack[$this->yyidx] = $x;
                        continue 2;
                    } elseif ($nextstate == self::YYNSTATE + self::YYNRULE + 1) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        // the last token was just ignored, we can't accept
                        // by ignoring input, this is in essence ignoring a
                        // syntax error!
                        return array_unique($expected);
                    } elseif ($nextstate === self::YY_NO_ACTION) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        // input accepted, but not shifted (I guess)
                        return $expected;
                    } else {
                        $yyact = $nextstate;
                    }
                } while (true);
            }
            break;
        } while (true);
        return array_unique($expected);
    }

    /**
     * Based on the parser state and current parser stack, determine whether
     * the lookahead token is possible.
     * 
     * The parser will convert the token value to an error token if not.  This
     * catches some unusual edge cases where the parser would fail.
     * @param int
     * @return bool
     */
    function yy_is_expected_token($token)
    {
        if ($token === 0) {
            return true; // 0 is not part of this
        }
        $state = $this->yystack[$this->yyidx]->stateno;
        if (in_array($token, self::$yyExpectedTokens[$state], true)) {
            return true;
        }
        $stack = $this->yystack;
        $yyidx = $this->yyidx;
        do {
            $yyact = $this->yy_find_shift_action($token);
            if ($yyact >= self::YYNSTATE && $yyact < self::YYNSTATE + self::YYNRULE) {
                // reduce action
                $done = 0;
                do {
                    if ($done++ == 100) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        // too much recursion prevents proper detection
                        // so give up
                        return true;
                    }
                    $yyruleno = $yyact - self::YYNSTATE;
                    $this->yyidx -= self::$yyRuleInfo[$yyruleno]['rhs'];
                    $nextstate = $this->yy_find_reduce_action(
                        $this->yystack[$this->yyidx]->stateno,
                        self::$yyRuleInfo[$yyruleno]['lhs']);
                    if (isset(self::$yyExpectedTokens[$nextstate]) &&
                          in_array($token, self::$yyExpectedTokens[$nextstate], true)) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        return true;
                    }
                    if ($nextstate < self::YYNSTATE) {
                        // we need to shift a non-terminal
                        $this->yyidx++;
                        $x = new SearchCommandParseryyStackEntry;
                        $x->stateno = $nextstate;
                        $x->major = self::$yyRuleInfo[$yyruleno]['lhs'];