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Diffstat (limited to 'wiki/inc/parser/lexer.php')
| -rw-r--r-- | wiki/inc/parser/lexer.php | 614 |
1 files changed, 614 insertions, 0 deletions
diff --git a/wiki/inc/parser/lexer.php b/wiki/inc/parser/lexer.php new file mode 100644 index 0000000..ba6a653 --- /dev/null +++ b/wiki/inc/parser/lexer.php @@ -0,0 +1,614 @@ +<?php +/** + * Author Markus Baker: http://www.lastcraft.com + * Version adapted from Simple Test: http://sourceforge.net/projects/simpletest/ + * For an intro to the Lexer see: + * https://web.archive.org/web/20120125041816/http://www.phppatterns.com/docs/develop/simple_test_lexer_notes + * @author Marcus Baker + * @package Doku + * @subpackage Lexer + * @version $Id: lexer.php,v 1.1 2005/03/23 23:14:09 harryf Exp $ + */ + +/** + * Init path constant + */ +if(!defined('DOKU_INC')) die('meh.'); + +/**#@+ + * lexer mode constant + */ +define("DOKU_LEXER_ENTER", 1); +define("DOKU_LEXER_MATCHED", 2); +define("DOKU_LEXER_UNMATCHED", 3); +define("DOKU_LEXER_EXIT", 4); +define("DOKU_LEXER_SPECIAL", 5); +/**#@-*/ + +/** + * Compounded regular expression. Any of + * the contained patterns could match and + * when one does it's label is returned. + * + * @package Doku + * @subpackage Lexer + */ +class Doku_LexerParallelRegex { + var $_patterns; + var $_labels; + var $_regex; + var $_case; + + /** + * Constructor. Starts with no patterns. + * + * @param boolean $case True for case sensitive, false + * for insensitive. + * @access public + */ + function __construct($case) { + $this->_case = $case; + $this->_patterns = array(); + $this->_labels = array(); + $this->_regex = null; + } + + /** + * Adds a pattern with an optional label. + * + * @param mixed $pattern Perl style regex. Must be UTF-8 + * encoded. If its a string, the (, ) + * lose their meaning unless they + * form part of a lookahead or + * lookbehind assertation. + * @param bool|string $label Label of regex to be returned + * on a match. Label must be ASCII + * @access public + */ + function addPattern($pattern, $label = true) { + $count = count($this->_patterns); + $this->_patterns[$count] = $pattern; + $this->_labels[$count] = $label; + $this->_regex = null; + } + + /** + * Attempts to match all patterns at once against a string. + * + * @param string $subject String to match against. + * @param string $match First matched portion of + * subject. + * @return boolean True on success. + * @access public + */ + function match($subject, &$match) { + if (count($this->_patterns) == 0) { + return false; + } + if (! preg_match($this->_getCompoundedRegex(), $subject, $matches)) { + $match = ""; + return false; + } + + $match = $matches[0]; + $size = count($matches); + for ($i = 1; $i < $size; $i++) { + if ($matches[$i] && isset($this->_labels[$i - 1])) { + return $this->_labels[$i - 1]; + } + } + return true; + } + + /** + * Attempts to split the string against all patterns at once + * + * @param string $subject String to match against. + * @param array $split The split result: array containing, pre-match, match & post-match strings + * @return boolean True on success. + * @access public + * + * @author Christopher Smith <chris@jalakai.co.uk> + */ + function split($subject, &$split) { + if (count($this->_patterns) == 0) { + return false; + } + + if (! preg_match($this->_getCompoundedRegex(), $subject, $matches)) { + if(function_exists('preg_last_error')){ + $err = preg_last_error(); + switch($err){ + case PREG_BACKTRACK_LIMIT_ERROR: + msg('A PCRE backtrack error occured. Try to increase the pcre.backtrack_limit in php.ini',-1); + break; + case PREG_RECURSION_LIMIT_ERROR: + msg('A PCRE recursion error occured. Try to increase the pcre.recursion_limit in php.ini',-1); + break; + case PREG_BAD_UTF8_ERROR: + msg('A PCRE UTF-8 error occured. This might be caused by a faulty plugin',-1); + break; + case PREG_INTERNAL_ERROR: + msg('A PCRE internal error occured. This might be caused by a faulty plugin',-1); + break; + } + } + + $split = array($subject, "", ""); + return false; + } + + $idx = count($matches)-2; + list($pre, $post) = preg_split($this->_patterns[$idx].$this->_getPerlMatchingFlags(), $subject, 2); + $split = array($pre, $matches[0], $post); + + return isset($this->_labels[$idx]) ? $this->_labels[$idx] : true; + } + + /** + * Compounds the patterns into a single + * regular expression separated with the + * "or" operator. Caches the regex. + * Will automatically escape (, ) and / tokens. + * + * @internal array $_patterns List of patterns in order. + * @return null|string + * @access private + */ + function _getCompoundedRegex() { + if ($this->_regex == null) { + $cnt = count($this->_patterns); + for ($i = 0; $i < $cnt; $i++) { + + /* + * decompose the input pattern into "(", "(?", ")", + * "[...]", "[]..]", "[^]..]", "[...[:...:]..]", "\x"... + * elements. + */ + preg_match_all('/\\\\.|' . + '\(\?|' . + '[()]|' . + '\[\^?\]?(?:\\\\.|\[:[^]]*:\]|[^]\\\\])*\]|' . + '[^[()\\\\]+/', $this->_patterns[$i], $elts); + + $pattern = ""; + $level = 0; + + foreach ($elts[0] as $elt) { + /* + * for "(", ")" remember the nesting level, add "\" + * only to the non-"(?" ones. + */ + + switch($elt) { + case '(': + $pattern .= '\('; + break; + case ')': + if ($level > 0) + $level--; /* closing (? */ + else + $pattern .= '\\'; + $pattern .= ')'; + break; + case '(?': + $level++; + $pattern .= '(?'; + break; + default: + if (substr($elt, 0, 1) == '\\') + $pattern .= $elt; + else + $pattern .= str_replace('/', '\/', $elt); + } + } + $this->_patterns[$i] = "($pattern)"; + } + $this->_regex = "/" . implode("|", $this->_patterns) . "/" . $this->_getPerlMatchingFlags(); + } + return $this->_regex; + } + + /** + * Accessor for perl regex mode flags to use. + * @return string Perl regex flags. + * @access private + */ + function _getPerlMatchingFlags() { + return ($this->_case ? "msS" : "msSi"); + } +} + +/** + * States for a stack machine. + * @package Lexer + * @subpackage Lexer + */ +class Doku_LexerStateStack { + var $_stack; + + /** + * Constructor. Starts in named state. + * @param string $start Starting state name. + * @access public + */ + function __construct($start) { + $this->_stack = array($start); + } + + /** + * Accessor for current state. + * @return string State. + * @access public + */ + function getCurrent() { + return $this->_stack[count($this->_stack) - 1]; + } + + /** + * Adds a state to the stack and sets it + * to be the current state. + * @param string $state New state. + * @access public + */ + function enter($state) { + array_push($this->_stack, $state); + } + + /** + * Leaves the current state and reverts + * to the previous one. + * @return boolean False if we drop off + * the bottom of the list. + * @access public + */ + function leave() { + if (count($this->_stack) == 1) { + return false; + } + array_pop($this->_stack); + return true; + } +} + +/** + * Accepts text and breaks it into tokens. + * Some optimisation to make the sure the + * content is only scanned by the PHP regex + * parser once. Lexer modes must not start + * with leading underscores. + * @package Doku + * @subpackage Lexer + */ +class Doku_Lexer { + var $_regexes; + var $_parser; + var $_mode; + var $_mode_handlers; + var $_case; + + /** + * Sets up the lexer in case insensitive matching + * by default. + * @param Doku_Parser $parser Handling strategy by + * reference. + * @param string $start Starting handler. + * @param boolean $case True for case sensitive. + * @access public + */ + function __construct($parser, $start = "accept", $case = false) { + $this->_case = $case; + /** @var Doku_LexerParallelRegex[] _regexes */ + $this->_regexes = array(); + $this->_parser = $parser; + $this->_mode = new Doku_LexerStateStack($start); + $this->_mode_handlers = array(); + } + + /** + * Adds a token search pattern for a particular + * parsing mode. The pattern does not change the + * current mode. + * @param string $pattern Perl style regex, but ( and ) + * lose the usual meaning. + * @param string $mode Should only apply this + * pattern when dealing with + * this type of input. + * @access public + */ + function addPattern($pattern, $mode = "accept") { + if (! isset($this->_regexes[$mode])) { + $this->_regexes[$mode] = new Doku_LexerParallelRegex($this->_case); + } + $this->_regexes[$mode]->addPattern($pattern); + } + + /** + * Adds a pattern that will enter a new parsing + * mode. Useful for entering parenthesis, strings, + * tags, etc. + * @param string $pattern Perl style regex, but ( and ) + * lose the usual meaning. + * @param string $mode Should only apply this + * pattern when dealing with + * this type of input. + * @param string $new_mode Change parsing to this new + * nested mode. + * @access public + */ + function addEntryPattern($pattern, $mode, $new_mode) { + if (! isset($this->_regexes[$mode])) { + $this->_regexes[$mode] = new Doku_LexerParallelRegex($this->_case); + } + $this->_regexes[$mode]->addPattern($pattern, $new_mode); + } + + /** + * Adds a pattern that will exit the current mode + * and re-enter the previous one. + * @param string $pattern Perl style regex, but ( and ) + * lose the usual meaning. + * @param string $mode Mode to leave. + * @access public + */ + function addExitPattern($pattern, $mode) { + if (! isset($this->_regexes[$mode])) { + $this->_regexes[$mode] = new Doku_LexerParallelRegex($this->_case); + } + $this->_regexes[$mode]->addPattern($pattern, "__exit"); + } + + /** + * Adds a pattern that has a special mode. Acts as an entry + * and exit pattern in one go, effectively calling a special + * parser handler for this token only. + * @param string $pattern Perl style regex, but ( and ) + * lose the usual meaning. + * @param string $mode Should only apply this + * pattern when dealing with + * this type of input. + * @param string $special Use this mode for this one token. + * @access public + */ + function addSpecialPattern($pattern, $mode, $special) { + if (! isset($this->_regexes[$mode])) { + $this->_regexes[$mode] = new Doku_LexerParallelRegex($this->_case); + } + $this->_regexes[$mode]->addPattern($pattern, "_$special"); + } + + /** + * Adds a mapping from a mode to another handler. + * @param string $mode Mode to be remapped. + * @param string $handler New target handler. + * @access public + */ + function mapHandler($mode, $handler) { + $this->_mode_handlers[$mode] = $handler; + } + + /** + * Splits the page text into tokens. Will fail + * if the handlers report an error or if no + * content is consumed. If successful then each + * unparsed and parsed token invokes a call to the + * held listener. + * @param string $raw Raw HTML text. + * @return boolean True on success, else false. + * @access public + */ + function parse($raw) { + if (! isset($this->_parser)) { + return false; + } + $initialLength = strlen($raw); + $length = $initialLength; + $pos = 0; + while (is_array($parsed = $this->_reduce($raw))) { + list($unmatched, $matched, $mode) = $parsed; + $currentLength = strlen($raw); + $matchPos = $initialLength - $currentLength - strlen($matched); + if (! $this->_dispatchTokens($unmatched, $matched, $mode, $pos, $matchPos)) { + return false; + } + if ($currentLength == $length) { + return false; + } + $length = $currentLength; + $pos = $initialLength - $currentLength; + } + if (!$parsed) { + return false; + } + return $this->_invokeParser($raw, DOKU_LEXER_UNMATCHED, $pos); + } + + /** + * Sends the matched token and any leading unmatched + * text to the parser changing the lexer to a new + * mode if one is listed. + * @param string $unmatched Unmatched leading portion. + * @param string $matched Actual token match. + * @param bool|string $mode Mode after match. A boolean + * false mode causes no change. + * @param int $initialPos + * @param int $matchPos + * Current byte index location in raw doc + * thats being parsed + * @return boolean False if there was any error + * from the parser. + * @access private + */ + function _dispatchTokens($unmatched, $matched, $mode = false, $initialPos, $matchPos) { + if (! $this->_invokeParser($unmatched, DOKU_LEXER_UNMATCHED, $initialPos) ){ + return false; + } + if ($this->_isModeEnd($mode)) { + if (! $this->_invokeParser($matched, DOKU_LEXER_EXIT, $matchPos)) { + return false; + } + return $this->_mode->leave(); + } + if ($this->_isSpecialMode($mode)) { + $this->_mode->enter($this->_decodeSpecial($mode)); + if (! $this->_invokeParser($matched, DOKU_LEXER_SPECIAL, $matchPos)) { + return false; + } + return $this->_mode->leave(); + } + if (is_string($mode)) { + $this->_mode->enter($mode); + return $this->_invokeParser($matched, DOKU_LEXER_ENTER, $matchPos); + } + return $this->_invokeParser($matched, DOKU_LEXER_MATCHED, $matchPos); + } + + /** + * Tests to see if the new mode is actually to leave + * the current mode and pop an item from the matching + * mode stack. + * @param string $mode Mode to test. + * @return boolean True if this is the exit mode. + * @access private + */ + function _isModeEnd($mode) { + return ($mode === "__exit"); + } + + /** + * Test to see if the mode is one where this mode + * is entered for this token only and automatically + * leaves immediately afterwoods. + * @param string $mode Mode to test. + * @return boolean True if this is the exit mode. + * @access private + */ + function _isSpecialMode($mode) { + return (strncmp($mode, "_", 1) == 0); + } + + /** + * Strips the magic underscore marking single token + * modes. + * @param string $mode Mode to decode. + * @return string Underlying mode name. + * @access private + */ + function _decodeSpecial($mode) { + return substr($mode, 1); + } + + /** + * Calls the parser method named after the current + * mode. Empty content will be ignored. The lexer + * has a parser handler for each mode in the lexer. + * @param string $content Text parsed. + * @param boolean $is_match Token is recognised rather + * than unparsed data. + * @param int $pos Current byte index location in raw doc + * thats being parsed + * @return bool + * @access private + */ + function _invokeParser($content, $is_match, $pos) { + if (($content === "") || ($content === false)) { + return true; + } + $handler = $this->_mode->getCurrent(); + if (isset($this->_mode_handlers[$handler])) { + $handler = $this->_mode_handlers[$handler]; + } + + // modes starting with plugin_ are all handled by the same + // handler but with an additional parameter + if(substr($handler,0,7)=='plugin_'){ + list($handler,$plugin) = explode('_',$handler,2); + return $this->_parser->$handler($content, $is_match, $pos, $plugin); + } + + return $this->_parser->$handler($content, $is_match, $pos); + } + + /** + * Tries to match a chunk of text and if successful + * removes the recognised chunk and any leading + * unparsed data. Empty strings will not be matched. + * @param string $raw The subject to parse. This is the + * content that will be eaten. + * @return array Three item list of unparsed + * content followed by the + * recognised token and finally the + * action the parser is to take. + * True if no match, false if there + * is a parsing error. + * @access private + */ + function _reduce(&$raw) { + if (! isset($this->_regexes[$this->_mode->getCurrent()])) { + return false; + } + if ($raw === "") { + return true; + } + if ($action = $this->_regexes[$this->_mode->getCurrent()]->split($raw, $split)) { + list($unparsed, $match, $raw) = $split; + return array($unparsed, $match, $action); + } + return true; + } +} + +/** + * Escapes regex characters other than (, ) and / + * + * @TODO + * + * @param string $str + * + * @return mixed + */ +function Doku_Lexer_Escape($str) { + //$str = addslashes($str); + $chars = array( + '/\\\\/', + '/\./', + '/\+/', + '/\*/', + '/\?/', + '/\[/', + '/\^/', + '/\]/', + '/\$/', + '/\{/', + '/\}/', + '/\=/', + '/\!/', + '/\</', + '/\>/', + '/\|/', + '/\:/' + ); + + $escaped = array( + '\\\\\\\\', + '\.', + '\+', + '\*', + '\?', + '\[', + '\^', + '\]', + '\$', + '\{', + '\}', + '\=', + '\!', + '\<', + '\>', + '\|', + '\:' + ); + return preg_replace($chars, $escaped, $str); +} + +//Setup VIM: ex: et ts=4 sw=4 : |