string ParsePropertyName(Expression expr, Token exprToken)
{
//Debug.Assert(expr != null);
string propName = null;
if (Token.Keyword == Keyword.As)
{
NextToken();
propName = Token.GetIdentifier();
if (propertyNames.Contains(propName))
{
throw Error.AliasNameAlreadyUsed(Token, propName);
}
NextToken();
}
else
{
switch (expr.NodeType)
{
case ExpressionType.MemberAccess:
propName = ((MemberExpression)expr).Member.Name;
break;
case ExpressionType.Call:
var call = ((MethodCallExpression)expr);
if (call.Method.Name == "get_Item" && call.Arguments.Count == 1 &&
call.Arguments[0].NodeType == ExpressionType.Constant)
{
propName = ((ConstantExpression)call.Arguments[0]).Value.ToString();
}
else
{
propName = call.Method.Name;
}
break;
case ExpressionType.Parameter:
propName = ((ParameterExpression)expr).Name;
break;
}
propName = UniquePropertyName(propName);
}
if (propName == null)
{
throw Error.ParseError(exprToken, Res.MissingAsClause);
}
Debug.Assert(propertyNames.Contains(propName) == false);
propertyNames.Add(propName);
return(propName);
}