<?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:
* http://www.phppatterns.com/index.php/article/articleview/106/1/2/
* @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 $case True for case sensitive, false
* for insensitive.
* @access public
*/
function Doku_LexerParallelRegex($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 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.
*
* @param array $patterns List of patterns in order.
* @access private
*/
function _getCompoundedRegex() {
if ($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 $start Starting state name.
* @access public
*/
function Doku_LexerStateStack($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 $case True for case sensitive.
* @access public
*/
function Doku_Lexer(&$parser, $start = "accept", $case = false) {
$this->_case = $case;
$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 string $mode Mode after match. A boolean
* false mode causes no change.
* @param int $pos Current byte index location in raw doc
* thats being parsed
* @return boolean False if there was any error
* from the parser.
* @access private
*/
function _dispatchTokens($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 $pos Current byte index location in raw doc
* thats being parsed
* @access private
*/
function _invokeParser($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, $action);
}
return true;
}
}
/**
* Escapes regex characters other than (, ) and /
* @TODO
*/
function Doku_Lexer_Escape($str) {
//$str = addslashes($str);
$chars = array(
'/\\\\/',
'/\./',
'/\+/',
'/\*/',
'/\?/',
'/\[/',
'/\^/',
'/\]/',
'/\$/',
'/\{/',
'/\}/',
'/\=/',
'/\!/',
'/\</',
'/\>/',
'/\|/',
'/\:/'
);
$escaped = array(
'\\\\\\\\',
'\.',
'\+',
'\*',
'\?',
'\[',
'\^',
'\]',
'\$',
'\{',
'\}',
'\=',
'\!',
'\<',
'\>',
'\|',
'\:'
);
return preg_replace($chars, $escaped, $str);
}
//Setup VIM: ex: et ts=4 sw=4 :