/// <summary>
/// Parser
/// </summary>
/// <returns>An AST</returns>
public Query Parse()
{
Where where = null;
OrderBy orderBy = null;
GroupBy groupBy = null;
_token = _scanner.GetToken();
if (_token.Ttype == TokenType.WHERE)
{
where = WhereRule();
}
if (_token.Ttype == TokenType.ORDERBY)
{
orderBy = OrderByRule();
}
if (_token.Ttype == TokenType.GROUPBY)
{
groupBy = GroupByRule();
}
Sequence sequence =
_astFactory.CreateSequence(where,
_astFactory.CreateSequence(orderBy,
_astFactory.CreateSequence(groupBy, null)));
Query expression = _astFactory.CreateQuery(sequence);
return(expression);
}