/**
* Handles a repetition token
*
* @param Token $token Token
*
* @return void
*/
protected function _handleRepetition(Token $token)
{
//If there is no current item, throw exception
if ($this->_currentItem === null) {
throw new Exception\InvalidRepetition("Nothing to repeat");
}
//Repetitions are allowed only after certain tokens, so check the last
//emitted token
$lastToken = $this->_tokensStack->top();
switch ($lastToken->getType()) {
//Handle lazy repetition
case Token::TYPE_REPETITION:
$prevLastToken = $this->_tokensStack->offsetGet(1);
//if this token is "?" and follows a repetition token that
//does not come after another repetition token set the lazy flag
if ($token->getIdentifier() === "?" && $prevLastToken->getType() !== Token::TYPE_REPETITION) {
//Check if last repetition supports the lazy flag
$lastRepetition = $this->_currentItem->getRepetition();
if ($lastRepetition->supportsLazy()) {
$lastRepetition->setLazy(true);
}
return;
} else {
throw new Exception\InvalidRepetition("Nothing to repeat");
}
break;
//Tokens that can handle the repetition
//Tokens that can handle the repetition
case Token::TYPE_NON_PRINTING_CHAR:
case Token::TYPE_GENERIC_CHAR_TYPE:
case Token::TYPE_CONTROL_CHAR:
case Token::TYPE_EXT_UNICODE_SEQUENCE:
case Token::TYPE_UNICODE_CHAR_CLASS:
case Token::TYPE_HEX_CHAR:
case Token::TYPE_DOT:
case Token::TYPE_BYTE:
case Token::TYPE_SUBPATTERN_END:
case Token::TYPE_COMMENT:
case Token::TYPE_OCTAL_CHAR:
case Token::TYPE_BACK_REFERENCE:
case Token::TYPE_CHAR_CLASS_END:
case Token::TYPE_RECURSIVE_PATTERN:
break;
//When simple characters are grouped, repetition is valid only
//for the last one, so it needs to be splitted so that the last
//character belongs to a different object
//When simple characters are grouped, repetition is valid only
//for the last one, so it needs to be splitted so that the last
//character belongs to a different object
case Token::TYPE_CHAR:
$chars = $this->_currentItem->getChar();
if (strlen($chars) > 1) {
$this->_currentItem->setChar(substr($chars, 0, -1));
$this->_currentItem = new Pattern\Char($chars[strlen($chars) - 1]);
$this->_containersStack->top()->addChild($this->_currentItem);
}
break;
default:
throw new Exception\InvalidRepetition("Repetition cannot be inserted at this point");
break;
}
//Get the right repetition class
switch ($token->getIdentifier()) {
case "*":
$repetition = new Pattern\Repetition\ZeroOrMore();
break;
case "+":
$repetition = new Pattern\Repetition\OneOrMore();
break;
case "?":
$repetition = new Pattern\Repetition\Optional();
break;
case "{":
//Check if {}
if (strpos($token->getSubject(), ",") === false) {
$repetition = new Pattern\Repetition\Number($token->getSubject());
} else {
$limits = explode(",", $token->getSubject());
$repetition = new Pattern\Repetition\Range($limits[0], $limits[1] === "" ? null : $limits[1]);
}
break;
}
//Set the repetition on the current item
$this->_currentItem->setRepetition($repetition);
}
/**
* Starts the tokenization proces
*
* @return void
*/
public function tokenize()
{
//Since delimiters are the only exception to the normal regex syntax and
//the tokenizer needs to know regex modifiers to handle some situations,
//parse them immediately and strip them from the regex
list($delimiter, $endDelimiter, $rModifiers) = $this->_stripDelimitersAndModifiers();
$checkEndDelimiter = $delimiter === $endDelimiter;
//Store regex length
$this->_length = strlen($this->_regex);
//Loop regex characters
while (($char = $this->_consume()) !== null) {
//If character is backslash and it's not escaped
if ($char === "\\" && !$this->_escaped) {
//Set escaped flag to true
$this->_escaped = true;
continue;
} elseif (!$this->_inCharClass && !$this->_escaped && $char === ".") {
//Emit a dot token
$this->_emitToken(Token::TYPE_DOT, $char);
} elseif ($this->_escaped && Rules::validateGenericCharType($char)) {
//Emit a generic character type token
$this->_emitToken(Token::TYPE_GENERIC_CHAR_TYPE, $char);
} elseif (!$this->_inCharClass && $this->_escaped && Rules::validateSimpleAssertion($char)) {
//Emit a simple assertion token
$this->_emitToken(Token::TYPE_SIMPLE_ASSERTION, $char);
} elseif ($this->_escaped && Rules::validateNonPrintingChar($char)) {
//Emit a non-printing character token
$this->_emitToken(Token::TYPE_NON_PRINTING_CHAR, $char);
} elseif (!$this->_inCharClass && $this->_escaped && $char === "X") {
//Emit a extended unicode sequence token
$this->_emitToken(Token::TYPE_EXT_UNICODE_SEQUENCE, $char);
} elseif (!$this->_inCharClass && $this->_escaped && $char === "C") {
//Emit a single byte identifier token
$this->_emitToken(Token::TYPE_BYTE, $char);
} elseif (!$this->_inCharClass && !$this->_escaped && ($char === "^" || $char === "\$")) {
//Emit an anchor token
$this->_emitToken($char === "^" ? Token::TYPE_START_ANCHOR : Token::TYPE_END_ANCHOR, $char);
} elseif (!$this->_inCharClass && !$this->_escaped && $char === "|") {
//Emit an alternation identifier token
$this->_emitToken(Token::TYPE_ALTERNATION, $char);
} elseif (!$this->_inCharClass && $this->_escaped && ($char === "p" || $char === "P")) {
//Take the next character
$nextChar = $this->_consume();
//If there are no characters left throw an exception
if ($nextChar === null) {
throw new Exception\Generic("Unspecified character class form \\" . $char);
} elseif ($nextChar !== "{") {
$this->_emitToken(Token::TYPE_UNICODE_CHAR_CLASS, $char, $nextChar);
} else {
//Find everything until the closing bracket
$nextChars = $this->_consumeUntil("}", true);
//If the closing bracket has not been found throw an
//exception
if ($nextChars === null) {
throw new Exception\Generic("Unclosed \\" . $char . " character class");
} else {
$this->_emitToken(Token::TYPE_UNICODE_CHAR_CLASS, $char, $nextChar . $nextChars);
}
}
} elseif ($this->_escaped && $char === "x") {
$nextChar = $this->_consume();
$tokenSubject = "";
if ($nextChar === "{") {
$nextChars = $this->_consumeUntil("}", true);
if ($nextChars === null) {
throw new Exception\Generic("Unclosed brace in hex char");
}
$tokenSubject = trim($nextChars, "}");
} elseif ($nextChar !== null) {
$this->_unconsume();
//Find following hexadecimal digits
for ($i = 0; $i < 2; $i++) {
$nextChar = $this->_consume();
if ($nextChar !== null && Rules::validateHexString($nextChar)) {
$tokenSubject .= $nextChar;
} else {
$nextChar !== null && $this->_unconsume();
break;
}
}
}
//Emit the hexadecimal character token
$this->_emitToken(Token::TYPE_HEX_CHAR, $char, $tokenSubject);
} elseif ($this->_escaped && $char === "c") {
//Take the next character
$nextChar = $this->_consumeIgnoreEscape();
//If there are no characters left throw an exception
if ($nextChar === null) {
throw new Exception\Generic("Character not specified for control character");
}
//Otherwise emit the control character token
$this->_emitToken(Token::TYPE_CONTROL_CHAR, $char, $nextChar);
} elseif (!$this->_inCharClass && !$this->_escaped && ($char === "*" || $char === "+" || $char === "?")) {
//Emit a repetition token
$this->_emitToken(Token::TYPE_REPETITION, $char);
} elseif (!$this->_inCharClass && !$this->_escaped && $char === "{" && ($nextChars = $this->_consumeRegex("/^\\d+(?:,\\d*)?\\}/"))) {
//Emit a repetition token
$this->_emitToken(Token::TYPE_REPETITION, $char, rtrim($nextChars, "}"));
} elseif (!$this->_inCharClass && !$this->_escaped && $char === "(") {
$this->_handleSubpattern();
} elseif (!$this->_inCharClass && !$this->_escaped && $char === ")") {
//Throw exception if there are no open subpatterns
if (!$this->_openSubpatterns) {
throw new Exception\Generic("Unmatched parenthesis");
}
//Emit a subpattern end token
$this->_emitToken(Token::TYPE_SUBPATTERN_END, $char);
$this->_openSubpatterns--;
$this->_modifiersStack->pop();
} elseif (!$this->_inCharClass && !$this->_escaped && $char === "[") {
//Emit a char class start token
$this->_emitToken(Token::TYPE_CHAR_CLASS_START, $char);
$this->_inCharClass = true;
//Consume next char
$char = $this->_consume();
//If the character is a char class negation
if ($char === "^") {
//Emit the char class negate token
$this->_emitToken(Token::TYPE_CHAR_CLASS_NEGATE, $char);
$char = $this->_consume();
}
//If the first char in a char class is a closed square bracket
if ($char === "]") {
//Emit the bracket as char token
$this->_emitToken(Token::TYPE_CHAR, $char);
} else {
$this->_unconsume();
}
} elseif ($this->_inCharClass && !$this->_escaped && $char === "]") {
//Emit a char class end token
$this->_emitToken(Token::TYPE_CHAR_CLASS_END, $char);
$this->_inCharClass = false;
} elseif ($this->_inCharClass && !$this->_escaped && $char === "-" && in_array($this->_lastToken->getType(), $this->_allowedInCharClassRange)) {
//Enable the after char class range mode
$this->_afterCharClassRange = true;
} elseif ($this->_inCharClass && !$this->_escaped && $char === "[" && ($nextChars = $this->_consumeRegex("/^:\\^?[a-z]+:\\]/"))) {
//Emit a posix char class token
$subject = str_replace(array(":", "]"), "", $nextChars);
$this->_emitToken(Token::TYPE_POSIX_CHAR_CLASS, $char . $nextChars, $subject);
} elseif (!$this->_inCharClass && $this->_escaped && ($char === "g" || $char === "k")) {
//It's a back reference. Check for the reference identifier
if ($char === "g") {
$testPattern = "(?|(\\d+)|\\{(-?\\d+|\\w+)\\})";
} else {
$testPattern = "(<\\w+>|'\\w+'|\\{\\w+\\})";
}
$nextChars = $this->_consumeRegex("/^{$testPattern}/", 1);
if ($nextChars === null) {
throw new Exception\Generic("Invalid backreference");
}
if ($char === "k") {
$nextChars = substr($nextChars, 1, -1);
}
//Check reference validity
if (!$this->_checkValidReference($nextChars)) {
throw new Exception\Generic("Reference to non-existent subpattern '{$nextChars}'");
}
//Emit a backreference token
$this->_emitToken(Token::TYPE_BACK_REFERENCE, $char, $nextChars);
} elseif ($this->_escaped && is_numeric($char)) {
//Char class does not handle back references so if the character
//is not octal process the character again without the escape
if ($this->_inCharClass && $char > 7) {
$this->_unconsume();
$this->_escaped = false;
continue;
}
//If the character is a 0 consume up to 2 octal digits,
//otherwise consume all the following digits
if ($char === "0" || $this->_inCharClass) {
$testPattern = "^[0-7]{1,2}";
} else {
$testPattern = "^\\d+";
}
//Consume following numbers
$nextChars = $this->_consumeRegex("/^{$testPattern}/");
if ($nextChars !== null) {
$char .= $nextChars;
}
//If the first digit is 0 or its a valid octal number and there
//are not enough back references
$hasReference = $this->_checkValidReference($char);
if ($char[0] === "0" || $this->_inCharClass || preg_match("/^[0-7]{2,3}\$/", $char) && !$hasReference) {
$this->_emitToken(Token::TYPE_OCTAL_CHAR, $char);
} elseif ($hasReference) {
//Emit a backreference token
$this->_emitToken(Token::TYPE_BACK_REFERENCE, "\\", $char);
} else {
throw new Exception\Generic("Reference to non-existent subpattern '{$char}'");
}
} elseif (!$this->_escaped && $checkEndDelimiter && $char === $endDelimiter) {
//Throw an exception
throw new Exception\InvalidDelimiter("Unescaped end delimiter '{$char}' inside regex");
} else {
//If the character is not escaped and the "x" modifier is active
if (!$this->_escaped && strpos($this->_modifiersStack->top(), "x") !== false) {
//If it is a "#"
if ($char === "#") {
//Emit a comment token
$nextChars = $this->_consumeUntil("\n");
if ($nextChars === null) {
$nextChars = $this->_consumeRemaining();
}
$this->_emitToken(Token::TYPE_COMMENT, $char, $nextChars);
continue;
} elseif (preg_match("/\\s/", $char)) {
continue;
}
}
//Emit the character as a simple pattern token
$this->_emitToken(Token::TYPE_CHAR, $char);
}
//Reset the escaped state
$this->_escaped = false;
}
//If the escaped state is already active it means that no end delimiter
//has been found, so an exception must be thrown
if ($this->_escaped) {
throw new Exception\InvalidDelimiter("End delimiter '{$endDelimiter}' not found");
}
//Throw exception if there are unclosed subpatterns
if ($this->_openSubpatterns) {
throw new Exception\Generic("The regex contains unclosed subpatterns");
}
//Throw exception if there are unclosed char classes
if ($this->_inCharClass) {
throw new Exception\Generic("The regex contains unclosed character classes");
}
//Emit the end delimiter token
$this->_emitToken(Token::TYPE_REGEX_END_DELIMITER, $endDelimiter);
//If regex modifiers were specified emit the token
if ($rModifiers) {
$this->_emitToken(Token::TYPE_REGEX_MODIFIERS, $rModifiers);
}
}
