private void TryParseFilterFunctionCall(SparqlQueryParserContext context, IToken t, GraphPattern p)
{
//Gather the Terms of the Function Call
Queue<IToken> funcTokens = new Queue<IToken>();
funcTokens.Enqueue(t);
int openBrackets = 0;
IToken next = context.Tokens.Peek();
do
{
if (next.TokenType == Token.LEFTBRACKET)
{
openBrackets++;
}
else if (next.TokenType == Token.RIGHTBRACKET)
{
openBrackets--;
}
funcTokens.Enqueue(next);
context.Tokens.Dequeue();
next = context.Tokens.Peek();
} while (openBrackets > 0);
UnaryExpressionFilter filter = new UnaryExpressionFilter(context.ExpressionParser.Parse(funcTokens));
p.IsFiltered = true;
p.AddFilter(filter);
}
private void TryParseFilterExists(SparqlQueryParserContext context, GraphPattern p, bool exists)
{
if (this._syntax == SparqlQuerySyntax.Sparql_1_0) throw new RdfParseException("EXISTS/NOT EXISTS is not supported in SPARQL 1.0");
//EXISTS/NOT EXISTS generate a new Graph Pattern
GraphPattern existsClause = this.TryParseGraphPattern(context);
UnaryExpressionFilter filter = new UnaryExpressionFilter(new ExistsFunction(existsClause, exists));
p.IsFiltered = true;
p.AddFilter(filter);
}
private void TryParseFilterBuiltInCall(SparqlQueryParserContext context, IToken t, GraphPattern p)
{
ISparqlFilter filter;
IToken next = context.Tokens.Dequeue();
//Should get a LeftBracket next
if (next.TokenType != Token.LEFTBRACKET)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered while trying to parse a Built-in Function call", next);
}
//Gather tokens for the FILTER expression
Queue<IToken> subtokens = new Queue<IToken>();
subtokens.Enqueue(t);
subtokens.Enqueue(next);
int openBrackets = 1;
while (openBrackets > 0)
{
next = context.Tokens.Dequeue();
if (next.TokenType == Token.LEFTBRACKET)
{
openBrackets++;
}
else if (next.TokenType == Token.RIGHTBRACKET)
{
openBrackets--;
}
subtokens.Enqueue(next);
}
ISparqlExpression expr = context.ExpressionParser.Parse(subtokens);
if (expr is BoundFunction)
{
filter = new BoundFilter((VariableExpressionTerm)expr.Arguments.First());
}
else
{
filter = new UnaryExpressionFilter(expr);
}
p.IsFiltered = true;
p.AddFilter(filter);
}
private void TryParseFilterRegex(SparqlQueryParserContext context, IToken t, GraphPattern p)
{
//Gather all the Tokens that make up the Regex
IToken next = context.Tokens.Peek();
Queue<IToken> regexTokens = new Queue<IToken>();
regexTokens.Enqueue(t);
int openBrackets = 0;
do
{
if (next.TokenType == Token.LEFTBRACKET)
{
openBrackets++;
}
else if (next.TokenType == Token.RIGHTBRACKET)
{
openBrackets--;
}
regexTokens.Enqueue(next);
context.Tokens.Dequeue();
next = context.Tokens.Peek();
} while (openBrackets > 0);
UnaryExpressionFilter filter = new UnaryExpressionFilter(context.ExpressionParser.Parse(regexTokens));
p.IsFiltered = true;
p.AddFilter(filter);
}
private void TryParseFilterExpression(SparqlQueryParserContext context, GraphPattern p)
{
UnaryExpressionFilter filter = new UnaryExpressionFilter(this.TryParseExpression(context, false));
p.IsFiltered = true;
p.AddFilter(filter);
}
