protected internal virtual FullTextQuery term(QueryScanner scanner)
{
FullTextQuery q = null;
switch (scanner.scan())
{
case QueryScanner.TKN_NOT:
q = term(scanner);
return((q != null) ? new FullTextQueryUnaryOp(FullTextQuery.Operator.Not, q) : null);
case QueryScanner.TKN_LPAR:
q = disjunction(scanner);
break;
case QueryScanner.TKN_WORD:
q = new FullTextQueryMatchOp(scanner.inQuotes ? FullTextQuery.Operator.StrictMatch : FullTextQuery.Operator.Match, scanner.word, scanner.wordPos);
break;
case QueryScanner.TKN_EOQ:
return(null);
default:
break;
}
scanner.scan();
return(q);
}
protected internal virtual FullTextQuery disjunction(QueryScanner scanner)
{
FullTextQuery left = conjunction(scanner);
if (scanner.token == QueryScanner.TKN_OR)
{
FullTextQuery right = disjunction(scanner);
if (left != null && right != null)
{
return(new FullTextQueryBinaryOp(FullTextQuery.Operator.Or, left, right));
}
else if (right != null)
{
return(right);
}
}
return(left);
}
protected internal virtual FullTextQuery conjunction(QueryScanner scanner)
{
FullTextQuery left = term(scanner);
if (scanner.token == QueryScanner.TKN_WORD || scanner.token == QueryScanner.TKN_AND)
{
if (scanner.token == QueryScanner.TKN_WORD)
{
scanner.unget = true;
}
FullTextQuery.Operator cop = scanner.inQuotes ? FullTextQuery.Operator.Near : FullTextQuery.Operator.And;
FullTextQuery right = disjunction(scanner);
if (left != null && right != null)
{
return(new FullTextQueryBinaryOp(cop, left, right));
}
else if (right != null)
{
return(right);
}
}
return(left);
}
/// <summary> Binary node constructor</summary>
/// <param name="op">operation code
/// </param>
/// <param name="left">left operand
/// </param>
/// <param name="right">right operand
/// </param>
public FullTextQueryBinaryOp(Operator op, FullTextQuery left, FullTextQuery right) : base(op)
{
this.left = left;
this.right = right;
}
public virtual void Visit(FullTextQuery q)
{
}
/// <summary> Unary node constructor</summary>
/// <param name="op">operation code
/// </param>
/// <param name="opd">operand
/// </param>
public FullTextQueryUnaryOp(Operator op, FullTextQuery opd) : base(op)
{
this.opd = opd;
}
/// <summary> Binary node constructor</summary>
/// <param name="op">operation code
/// </param>
/// <param name="left">left operand
/// </param>
/// <param name="right">right operand
/// </param>
public FullTextQueryBinaryOp(Operator op, FullTextQuery left, FullTextQuery right):base(op)
{
this.left = left;
this.right = right;
}
public virtual void Visit(FullTextQuery q)
{
}
/// <summary> Unary node constructor</summary>
/// <param name="op">operation code
/// </param>
/// <param name="opd">operand
/// </param>
public FullTextQueryUnaryOp(Operator op, FullTextQuery opd):base(op)
{
this.opd = opd;
}
