/**
* Throw a syntax error
*
* @param string $expected
* @throws ParserException
*/
private function syntaxError($expected)
{
$token = $this->lexer->lookahead;
$tokenPosition = isset($token['position']) ? $token['position'] : '-1';
$message = sprintf('line 0, col %s: Error: Expected %s, got ', $tokenPosition, $expected);
if ($this->lexer->lookahead === null) {
$message .= 'end of string';
} else {
$message .= $this->lexer->getLiteral($token['type']);
}
throw new ParserException($message);
}
/**
* Attempts to match the given token with the current lookahead token.
*
* If they match, updates the lookahead token; otherwise raises a syntax
* error.
*
* @param int $token The token type.
*
* @return void
*
* @throws StatementException If the tokens don't match.
*/
public function match($token)
{
$lookaheadType = $this->lexer->lookahead['type'];
// Short-circuit on first condition, usually types match
if ($lookaheadType !== $token) {
// If parameter is not identifier (1-99) must be exact match
if ($token < Lexer::T_IDENTIFIER) {
$this->syntaxError($this->lexer->getLiteral($token));
}
// If parameter is keyword (200+) must be exact match
if ($token > Lexer::T_IDENTIFIER) {
$this->syntaxError($this->lexer->getLiteral($token));
}
// If parameter is MATCH then FULL, PARTIAL or SIMPLE must follow
if ($token === Lexer::T_MATCH && $lookaheadType !== Lexer::T_FULL && $lookaheadType !== Lexer::T_PARTIAL && $lookaheadType !== Lexer::T_SIMPLE) {
$this->syntaxError($this->lexer->getLiteral($token));
}
if ($token === Lexer::T_ON && $lookaheadType !== Lexer::T_DELETE && $lookaheadType !== Lexer::T_UPDATE) {
$this->syntaxError($this->lexer->getLiteral($token));
}
}
$this->lexer->moveNext();
}
