public static function parse($tokenStream, $dataContext)
{
$scopes = array();
$expression = new PrimitiveExp(new Token('final'));
while ($token = array_shift($tokenStream)) {
// split non-primitive expression into primitive ones
switch ($token->type) {
case ExpType::$PAREN:
switch ($token->value) {
case '[':
$expression->append(new Token(ExpType::$DOT, '.'));
// drop through
// drop through
case '(':
ExpParser::scopePush($expression, $scopes, $token);
break;
case ']':
if ($expression->reason->value != '[') {
throw new ExpParserException("Unbalanced [], should be detected in Lexer");
}
ExpParser::scopePop($expression, $scopes, $dataContext);
break;
case ')':
if ($expression->reason->value != '(') {
throw new ExpParserException("Unbalanced (), should be detected in Lexer");
}
ExpParser::scopePop($expression, $scopes, $dataContext);
// close if it's a function
if ($expression->reason->type == ExpType::$FUNCTION) {
ExpParser::scopePop($expression, $scopes, $dataContext);
}
break;
default:
throw new ExpParserException("Token error: " . print_r($token, true));
}
break;
case ExpType::$FUNCTION:
ExpParser::scopePush($expression, $scopes, $token);
break;
case ExpType::$TERNARY:
if ($token->value != '?') {
throw new ExpParserException("Ternary token error");
}
$nextTernary = ExpParser::findNextTernary($tokenStream, 1);
$indicator = ExpType::coerceToBool($expression->evaluate($dataContext));
if ($indicator->value) {
// parsed?todo:skip
$nextCloseSymbol = ExpParser::findNextCloseSymbol($tokenStream, $nextTernary + 1);
array_splice($tokenStream, $nextTernary, $nextCloseSymbol - $nextTernary);
} else {
// parsed?skip:todo
$tokenStream = array_slice($tokenStream, $nextTernary + 1);
}
$expression = new PrimitiveExp($expression->reason);
break;
case ExpType::$COMMA:
if ($expression->reason->value != '(') {
throw new ExpParserException("Unbalanced (), should be detected in Lexer");
}
ExpParser::scopePop($expression, $scopes, $dataContext);
ExpParser::scopePush($expression, $scopes, new Token(ExpType::$PAREN, '('));
break;
default:
$expression->append($token);
}
}
if ($expression->reason->type != 'final') {
throw new ExpParserException("Gramma error on the non-primitive expression");
}
return $expression->evaluate($dataContext);
}
