/**
* 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;
}
