private static QueryParserNode BuildTree(IList subtokens, QueryParserNode.Type opCode)
{
QueryParserNode node = new TermNode((string)subtokens[subtokens.Count - 1]);
for (int i = subtokens.Count - 2; i >= 0; i--)
{
TermNode leftOpnd = new TermNode((string)subtokens[i]);
OpNode op = new OpNode(opCode);
op.AddOperand(leftOpnd);
op.AddOperand(node);
node = op;
}
return(node);
}
private static QueryParserNode SplitTokenToTree(string token)
{
ArrayList subtokens = SplitTokens(token);
QueryParserNode node;
// 1. If there are no tokens - the input string completely consists
// of delimiter symbols.
// 2. If there is only one token - then delimiter symbols either started
// or closed the string.
if (subtokens.Count == 0)
{
node = new TermNode(token);
}
else if (subtokens.Count == 1)
{
// check if wildcard
if (token.EndsWith("*") || token.EndsWith("?"))
{
ArrayList tokens = Word.GetTokensByWildcard(token);
if (tokens.Count > 0)
{
node = BuildTree(tokens, QueryParserNode.Type.eoOr);
}
else
{
node = new TermNode(token);
}
}
else
{
node = new TermNode((string)subtokens[0]);
}
}
else
{
node = BuildTree(subtokens, QueryParserNode.Type.eoPhraseNear);
}
return(node);
}
private static QueryParserNode ProcessPrimaryLevel()
{
QueryParserNode nodePrimaryToken = null;
GetNextToken();
if (strToken != "")
{
if (strToken == "(")
{
nodePrimaryToken = ParseExpression();
_errorMessage = "Error in the query syntax - expected ')' symbol in expression";
Expect(")");
_errorMessage = null;
}
else
if (strToken == "\"+")
{
isPhrasalMode = true;
nodePrimaryToken = ParseExpression();
Expect("+\"");
isPhrasalMode = false;
}
else
{
string normToken = OMEnv.LexemeConstructor.GetNormalizedToken(strToken);
if (isDelimitableToken(normToken))
{
nodePrimaryToken = SplitTokenToTree(normToken);
}
else
{
nodePrimaryToken = new TermNode(normToken);
}
}
}
return(nodePrimaryToken);
}