/**
* Skips whitespace in the specified text by advancing an index to
* the next non-whitespace character.
*
* @param string $text Text to scan.
* @param int &$textIndex Index to begin scanning from.
*
* @return boolean true if the end of the string was reached, false otherwise.
*/
public static function skipWhiteSpace($text, &$textIndex)
{
$textLen = strlen($text);
while ($textIndex < $textLen && Char::isWhiteSpace($text[$textIndex])) {
$textIndex++;
}
return $textLen == $textIndex;
}
/**
* Reads the next token, skipping whitespace as necessary.
*
* @return void
*/
public function nextToken()
{
while (Char::isWhiteSpace($this->_ch)) {
$this->_nextChar();
}
$t;
$tokenPos = $this->_textPos;
switch ($this->_ch) {
case '(':
$this->_nextChar();
$t = ExpressionTokenId::OPENPARAM;
break;
case ')':
$this->_nextChar();
$t = ExpressionTokenId::CLOSEPARAM;
break;
case ',':
$this->_nextChar();
$t = ExpressionTokenId::COMMA;
break;
case '-':
$hasNext = $this->_textPos + 1 < $this->_textLen;
if ($hasNext && Char::isDigit($this->_text[$this->_textPos + 1])) {
$this->_nextChar();
$t = $this->_parseFromDigit();
if (self::isNumeric($t)) {
break;
}
$this->_setTextPos($tokenPos);
} else {
if ($hasNext && $this->_text[$tokenPos + 1] == 'I') {
$this->_nextChar();
$this->_parseIdentifier();
$currentIdentifier = substr($this->_text, $tokenPos + 1, $this->_textPos - $tokenPos - 1);
if (self::_isInfinityLiteralDouble($currentIdentifier)) {
$t = ExpressionTokenId::DOUBLE_LITERAL;
break;
} else {
if (self::_isInfinityLiteralSingle($currentIdentifier)) {
$t = ExpressionTokenId::SINGLE_LITERAL;
break;
}
}
// If it looked like '-INF' but wasn't we'll rewind and fall
// through to a simple '-' token.
$this->_setTextPos($tokenPos);
}
}
$this->_nextChar();
$t = ExpressionTokenId::MINUS;
break;
case '=':
$this->_nextChar();
$t = ExpressionTokenId::EQUAL;
break;
case '/':
$this->_nextChar();
$t = ExpressionTokenId::SLASH;
break;
case '?':
$this->_nextChar();
$t = ExpressionTokenId::QUESTION;
break;
case '.':
$this->_nextChar();
$t = ExpressionTokenId::DOT;
break;
case '\'':
$quote = $this->_ch;
do {
$this->_nextChar();
while ($this->_textPos < $this->_textLen && $this->_ch != $quote) {
$this->_nextChar();
}
if ($this->_textPos == $this->_textLen) {
throw $this->_parseError(Messages::expressionLexerUnterminatedStringLiteral($this->_textPos, $this->_text));
}
$this->_nextChar();
} while ($this->_ch == $quote);
$t = ExpressionTokenId::STRING_LITERAL;
break;
case '*':
$this->_nextChar();
$t = ExpressionTokenId::STAR;
break;
default:
if (Char::isLetter($this->_ch) || $this->_ch == '_') {
$this->_parseIdentifier();
$t = ExpressionTokenId::IDENTIFIER;
break;
}
if (Char::isDigit($this->_ch)) {
$t = $this->_parseFromDigit();
break;
}
if ($this->_textPos == $this->_textLen) {
$t = ExpressionTokenId::END;
break;
}
throw $this->_parseError(Messages::expressionLexerInvalidCharacter($this->_ch, $this->_textPos));
}
$this->_token->Id = $t;
$this->_token->Text = substr($this->_text, $tokenPos, $this->_textPos - $tokenPos);
$this->_token->Position = $tokenPos;
// Handle type-prefixed literals such as binary, datetime or guid.
$this->_handleTypePrefixedLiterals();
// Handle keywords.
if ($this->_token->Id == ExpressionTokenId::IDENTIFIER) {
if (self::_isInfinityOrNaNDouble($this->_token->Text)) {
$this->_token->Id = ExpressionTokenId::DOUBLE_LITERAL;
} else {
if (self::_isInfinityOrNanSingle($this->_token->Text)) {
$this->_token->Id = ExpressionTokenId::SINGLE_LITERAL;
} else {
if ($this->_token->Text == ODataConstants::KEYWORD_TRUE || $this->_token->Text == ODataConstants::KEYWORD_FALSE) {
$this->_token->Id = ExpressionTokenId::BOOLEAN_LITERAL;
} else {
if ($this->_token->Text == ODataConstants::KEYWORD_NULL) {
$this->_token->Id = ExpressionTokenId::NULL_LITERAL;
}
}
}
}
}
}
