private ExpressionNode parseQueryExpression() {
var restorePoint = this.createRestorePoint();
var result = new QueryExpressionNode();
setScannerState(result);
var doParseType = true;
var lex = nextLexicalUnit(false);
if (!(isIdentifier(lex) || (lex == LexicalUnit.Keyword && scanner.Keyword == Keyword.String))) {
this.restore(restorePoint);
return null;
} else {
int sp = scanner.StartPosition;
int len = getLexicalUnitLength();
switch (nextLexicalUnit(false)) {
case SemiColon:
case Assign:
case Comma:
this.restore(restorePoint);
return null;
case Keyword:
if (scanner.Keyword == Keyword.In) {
doParseType = false;
result.From.NameOffset = sp;
result.From.NameLength = len;
break;
}
goto default;
default:
this.restore(restorePoint);
nextLexicalUnit(true);
break;
}
}
if (doParseType) {
result.From.Type = parseType(false);
if (result.From.Type == null) {
this.restore(restorePoint);
return null;
}
if (!isIdentifier(lexicalUnit)) {
this.restore(restorePoint);
return null;
}
result.From.NameOffset = scanner.StartPosition;
result.From.NameLength = getLexicalUnitLength();
nextLexicalUnit(true);
}
if (lexicalUnit != LexicalUnit.Keyword || scanner.Keyword != Keyword.In) {
throw error(ParseErrorId.InExpected);
}
nextLexicalUnit(true);
result.From.Origin = parseExpression();
parseQueryBody(result.Body, result.From.Origin.EndPosition);
result.EndPosition = result.Body.EndPosition;
return result;
}
protected virtual TResult handleQuery(QueryExpressionNode query, TSource source, bool nested)
{
return(defaultHandler());
}