private void SubQueryCondition(QueryTree queryTree)
{
PredicateCondition(queryTree);
if (_lookaheadFirst.TokenType == TokenType.And)
{
queryTree.Insert(FilterQueryLogicalOperator.and);
DiscardToken();
SubQueryCondition(queryTree);
}
if (_lookaheadFirst.TokenType == TokenType.Or)
{
queryTree.Insert(FilterQueryLogicalOperator.or);
DiscardToken();
SubQueryCondition(queryTree);
}
}
private void PredicateCondition(QueryTree queryTree)
{
var predicate = new PredicateModel();
if (_lookaheadFirst.Value == null)
{
throw new ApplicationException("Illegal query detected, enclose strings with a beginning ' and ending '");
}
predicate.Field = _lookaheadFirst.Value;
DiscardToken();
predicate.Operator = GetOperator(_lookaheadFirst);
DiscardToken();
predicate.Value = _lookaheadFirst.Value;
DiscardToken();
queryTree.Insert(predicate);
}
public QueryTree Parse(List <Token> tokens)
{
LoadSequenceStack(tokens);
PrepareLookaheads();
_queryTree = new List <QueryTree>();
Find();
DiscardToken(TokenType.SequenceTerminator);
var qtToReturn = new QueryTree();
foreach (var qt in _queryTree)
{
qtToReturn.Insert(qt.GetRoot());
}
return(qtToReturn);
}
private void FindCondition()
{
var queryTree = new QueryTree();
if (_lookaheadFirst.TokenType == TokenType.OpenParenthesis)
{
DiscardToken();
SubQueryCondition(queryTree);
DiscardToken();
_queryTree.Add(queryTree);
}
var op = GetLogicalOperator(_lookaheadFirst);
if (op != null)
{
var singleNodeQT = new QueryTree();
singleNodeQT.Insert(op.Value);
_queryTree.Add(singleNodeQT);
DiscardToken();
FindCondition();
}
}