/**
* Parse a reference
*/
public function evaluate(Lexer $lexer)
{
switch (true) {
case $lexer->isNextToken(Lexer::T_SHORT_P):
throw new ParserException('Property \\p (Unicode Property) not supported use \\x to specify unicode character or range');
break;
case $lexer->isNextToken(Lexer::T_SHORT_UNICODE_X):
$lexer->moveNext();
if ($lexer->lookahead['value'] !== '{') {
throw new ParserException('Expecting character { after \\X none found');
}
$tokens = array();
while ($lexer->moveNext() && $lexer->lookahead['value'] !== '}') {
# check if we nested eg.{ddd{d}
if ($lexer->lookahead['value'] === '{') {
throw new ParserException('Nesting hex value ranges is not allowed');
}
if ($lexer->lookahead['value'] !== " " && ctype_xdigit($lexer->lookahead['value']) === false) {
throw new ParserException(sprintf('Character %s is not a hexdeciaml digit', $lexer->lookahead['value']));
}
$tokens[] = $lexer->lookahead['value'];
}
# check that current lookahead is a closing character as it's possible to iterate to end of string (i.e. lookahead === null)
if ($lexer->lookahead['value'] !== '}') {
throw new ParserException('Closing quantifier token `}` not found');
}
if (count($tokens) === 0) {
throw new ParserException('No hex number found inside the range');
}
$number = trim(implode('', $tokens));
return Utf8::chr(hexdec($number));
break;
case $lexer->isNextToken(Lexer::T_SHORT_X):
// only allow another 2 hex characters
$glimpse = $lexer->glimpse();
if ($glimpse['value'] === '{') {
throw new ParserException('Braces not supported here');
}
$tokens = array();
$count = 2;
while ($count > 0 && $lexer->moveNext()) {
$tokens[] = $lexer->lookahead['value'];
--$count;
}
$value = trim(implode('', $tokens));
return Utf8::chr(hexdec($value));
break;
default:
throw new ParserException('No Unicode expression to evaluate');
}
}
/**
* Parse the current token for new Quantifiers
*
* @access public
* @return ReverseRegex\Generator\Scope a new head
* @param ReverseRegex\Generator\Scope $head
* @param ReverseRegex\Generator\Scope $set
* @param ReverseRegex\Lexer $lexer
*/
public function parse(Scope $head, Scope $set, Lexer $lexer)
{
if ($lexer->lookahead['type'] !== Lexer::T_SET_OPEN) {
throw new ParserException('Opening character set token not found');
}
$peek = $lexer->glimpse();
if ($peek['type'] === Lexer::T_SET_NEGATED) {
throw new ParserException('Negated Character Set ranges not supported at this time');
}
$normal_lexer = new Lexer($this->normalize($head, $set, $lexer));
while ($normal_lexer->moveNext() && !$normal_lexer->isNextToken(Lexer::T_SET_CLOSE)) {
$glimpse = $normal_lexer->glimpse();
if ($glimpse['type'] === Lexer::T_SET_RANGE) {
continue;
//value be included in range when `-` character is passed
}
switch (true) {
case $normal_lexer->isNextToken(Lexer::T_SET_RANGE):
$range_start = $normal_lexer->token['value'];
$normal_lexer->moveNext();
if ($normal_lexer->isNextToken(Lexer::T_ESCAPE_CHAR)) {
$normal_lexer->moveNext();
}
$range_end = $normal_lexer->lookahead['value'];
$this->fillRange($head, $range_start, $range_end);
break;
case $normal_lexer->isNextToken(Lexer::T_LITERAL_NUMERIC) || $normal_lexer->isNextToken(Lexer::T_LITERAL_CHAR):
$index = (int) Utf8::ord($normal_lexer->lookahead['value']);
$head->setLiteral($index, $normal_lexer->lookahead['value']);
break;
default:
# ignore
}
}
$head->getLiterals()->sort();
return $head;
}
/**
* Will parse the regex into generator
*
* @access public
* @return
*/
public function parse($sub = false)
{
try {
while ($this->lexer->moveNext()) {
$result = null;
$scope = null;
$parser = null;
switch (true) {
case $this->lexer->isNextToken(Lexer::T_GROUP_OPEN):
# is the group character the first token? is the regex wrapped in brackets.
//if($this->lexer->token === null) {
// continue;
//}
# note this is a new group create new parser instance.
$parser = new Parser($this->lexer, new Scope(), new Scope());
$this->left = $parser->parse(true)->getResult();
$this->head->attach($this->left);
break;
case $this->lexer->isNextToken(Lexer::T_GROUP_CLOSE):
# group is finished don't want to contine this loop break = 2
break 2;
break;
case $this->lexer->isNextTokenAny(array(Lexer::T_LITERAL_CHAR, Lexer::T_LITERAL_NUMERIC)):
# test for literal characters (abcd)
$this->left = new LiteralScope();
$this->left->addLiteral($this->lexer->lookahead['value']);
$this->head->attach($this->left);
break;
case $this->lexer->isNextToken(Lexer::T_SET_OPEN):
# character classes [a-z]
$this->left = new LiteralScope();
self::createSubParser('character')->parse($this->left, $this->head, $this->lexer);
$this->head->attach($this->left);
break;
case $this->lexer->isNextTokenAny(array(Lexer::T_DOT, Lexer::T_SHORT_D, Lexer::T_SHORT_NOT_D, Lexer::T_SHORT_W, Lexer::T_SHORT_NOT_W, Lexer::T_SHORT_S, Lexer::T_SHORT_NOT_S)):
# match short (. \d \D \w \W \s \S)
$this->left = new LiteralScope();
self::createSubParser('short')->parse($this->left, $this->head, $this->lexer);
$this->head->attach($this->left);
break;
case $this->lexer->isNextTokenAny(array(Lexer::T_SHORT_P, Lexer::T_SHORT_UNICODE_X, Lexer::T_SHORT_X)):
# match short (\p{L} \x \X )
$this->left = new LiteralScope();
self::createSubParser('unicode')->parse($this->left, $this->head, $this->lexer);
$this->head->attach($this->left);
break;
case $this->lexer->isNextTokenAny(array(Lexer::T_QUANTIFIER_OPEN, Lexer::T_QUANTIFIER_PLUS, Lexer::T_QUANTIFIER_QUESTION, Lexer::T_QUANTIFIER_STAR, Lexer::T_QUANTIFIER_OPEN)):
# match quantifiers
self::createSubParser('quantifer')->parse($this->left, $this->head, $this->lexer);
break;
case $this->lexer->isNextToken(Lexer::T_CHOICE_BAR):
# match alternations
$this->left = $this->head;
$this->head = new Scope();
$this->result->useAlternatingStrategy();
$this->result->attach($this->head);
break;
default:
# ignore character
}
}
} catch (ParserException $e) {
$pos = $this->lexer->lookahead['position'];
$compressed = $this->compress();
throw new ParserException(sprintf('Error found STARTING at position %s after `%s` with msg %s ', $pos, $compressed, $e->getMessage()));
}
return $this;
}
public function convertWhiteSpaceToRange(Scope $head, Scope $result, Lexer $lexer)
{
if ($lexer->isNextToken(Lexer::T_SHORT_S)) {
# spaces, tabs, and line breaks
#0009 #0010 #0012 #0013 #0032
$head->addLiteral(chr(9));
$head->addLiteral(chr(10));
$head->addLiteral(chr(12));
$head->addLiteral(chr(13));
$head->addLiteral(chr(32));
} else {
# not spaces, tabs, and line breaks
#0000-0008 #0011 #0014 - #0031
for ($i = 0; $i <= 8; $i++) {
$head->addLiteral(chr($i));
}
$head->addLiteral(chr(11));
for ($i = 14; $i <= 31; $i++) {
$head->addLiteral(chr($i));
}
}
}
/**
* Parse the current token for closers : {###} { ## } {##,##}
*
* @access public
* @return ReverseRegex\Generator\Scope a new head
* @param ReverseRegex\Generator\Scope $head
* @param ReverseRegex\Generator\Scope $result
* @param ReverseRegex\Lexer $lexer
*/
public function quantifyClosure(Scope $head, Scope $result, Lexer $lexer)
{
$tokens = array();
$min = $head->getMinOccurances();
$max = $head->getMaxOccurances();
# move to the first token inside the quantifer.
# parse for the minimum , move lookahead until read end of the closure or the `,`
while ($lexer->moveNext() === true && !$lexer->isNextToken(Lexer::T_QUANTIFIER_CLOSE) && $lexer->lookahead['value'] !== ',') {
if ($lexer->isNextToken(Lexer::T_QUANTIFIER_OPEN)) {
throw new ParserException('Nesting Quantifiers is not allowed');
}
$tokens[] = $lexer->lookahead;
}
$min = $this->convertInteger($tokens);
# do we have a maximum after the comma?
if ($lexer->lookahead['value'] === ',') {
# make sure we have values to gather ie not {778,}
$tokens = array();
# move to the first token after the `,` character
# grab the remaining numbers
while ($lexer->moveNext() && !$lexer->isNextToken(Lexer::T_QUANTIFIER_CLOSE)) {
if ($lexer->isNextToken(Lexer::T_QUANTIFIER_OPEN)) {
throw new ParserException('Nesting Quantifiers is not allowed');
}
$tokens[] = $lexer->lookahead;
}
$max = $this->convertInteger($tokens);
} else {
$max = $min;
}
$head->setMaxOccurances($max);
$head->setMinOccurances($min);
# skip the lexer to the closing token
$lexer->skipUntil(Lexer::T_QUANTIFIER_CLOSE);
# check if the last matched token was the closing bracket
# not going to stop errors like {#####,###{[a-z]} {#####{[a-z]}
if (!$lexer->isNextToken(Lexer::T_QUANTIFIER_CLOSE)) {
throw new ParserException('Closing quantifier token `}` not found');
}
return $head;
}
