コード例 #1
0
        /// <summary>
        /// Tries to create a SPARQL Function expression if the function Uri correseponds to a supported SPARQL Function.
        /// </summary>
        /// <param name="u">Function Uri.</param>
        /// <param name="args">Function Arguments.</param>
        /// <param name="scalarArguments">Scalar Arguments.</param>
        /// <param name="expr">Generated Expression.</param>
        /// <returns>Whether an expression was successfully generated.</returns>
        public bool TryCreateExpression(Uri u, List <ISparqlExpression> args, Dictionary <string, ISparqlExpression> scalarArguments, out ISparqlExpression expr)
        {
            String func = u.ToString();

            if (func.StartsWith(SparqlFunctionsNamespace))
            {
                func = func.Substring(SparqlFunctionsNamespace.Length);
                func = func.ToUpper();

                // If any Scalar Arguments are present then can't be a SPARQL Function UNLESS it is
                // a GROUP_CONCAT function and it has the SEPARATOR argument
                if (scalarArguments.Count > 0)
                {
                    if (func.Equals(SparqlSpecsHelper.SparqlKeywordGroupConcat) && scalarArguments.Count == 1 && scalarArguments.ContainsKey(SparqlSpecsHelper.SparqlKeywordSeparator))
                    {
                        // OK
                    }
                    else
                    {
                        expr = null;
                        return(false);
                    }
                }

                // Q: Will there be special URIs for the DISTINCT modified forms of aggregates?

                ISparqlExpression sparqlFunc = null;
                switch (func)
                {
                case SparqlSpecsHelper.SparqlKeywordAbs:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new AbsFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ABS() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordAvg:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new AggregateTerm(new AverageAggregate(args.First()));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL AVG() aggregate");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordBound:
                    if (args.Count == 1)
                    {
                        if (args[0] is VariableTerm)
                        {
                            sparqlFunc = new BoundFunction((VariableTerm)args[0]);
                        }
                        else
                        {
                            throw new RdfParseException("The SPARQL BOUND() function only operates over Variables");
                        }
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL BOUND() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordCeil:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new CeilFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL CEIL() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordCoalesce:
                    if (args.Count >= 1)
                    {
                        sparqlFunc = new CoalesceFunction(args);
                    }
                    else
                    {
                        throw new RdfParseException("The SPARQL COALESCE() function requires at least 1 argument");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordConcat:
                    if (args.Count >= 1)
                    {
                        sparqlFunc = new ConcatFunction(args);
                    }
                    else
                    {
                        throw new RdfParseException("The SPARQL CONCAT() function requires at least 1 argument");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordContains:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new ContainsFunction(args[0], args[1]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL CONTAINS() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordCount:
                    // Q: What will the URIs be for the special forms of COUNT?
                    if (args.Count == 1)
                    {
                        sparqlFunc = new AggregateTerm(new CountAggregate(args.First()));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL COUNT() aggregate");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordDataType:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new DataTypeFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL DATATYPE() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordDay:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new DayFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL DAY() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordEncodeForUri:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new EncodeForUriFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ENCODE_FOR_URI() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordFloor:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new FloorFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL FLOOR() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordGroupConcat:
                    if (args.Count == 1)
                    {
                        if (scalarArguments.ContainsKey(SparqlSpecsHelper.SparqlKeywordSeparator))
                        {
                            sparqlFunc = new AggregateTerm(new GroupConcatAggregate(args.First(), scalarArguments[SparqlSpecsHelper.SparqlKeywordSeparator]));
                        }
                        else
                        {
                            sparqlFunc = new AggregateTerm(new GroupConcatAggregate(args.First()));
                        }
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL GROUP_CONCAT() aggregate");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordHours:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new HoursFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL HOURS() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordIf:
                    if (args.Count == 3)
                    {
                        sparqlFunc = new IfElseFunction(args[0], args[1], args[2]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL IF() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordIri:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new IriFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL IRI() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordIsBlank:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new IsBlankFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ISBLANK() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordIsIri:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new IsIriFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ISIRI() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordIsLiteral:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new IsLiteralFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ISLITERAL() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordIsNumeric:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new IsNumericFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ISNUMERIC() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordIsUri:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new IsUriFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ISURI() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordLang:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new LangFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL LANG() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordLangMatches:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new LangMatchesFunction(args[0], args[1]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL LANGMATCHES() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordLCase:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new LCaseFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL LCASE() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordMax:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new AggregateTerm(new MaxAggregate(args.First()));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL MAX() aggregate");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordMD5:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new MD5HashFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL MD5() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordMin:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new AggregateTerm(new MinAggregate(args.First()));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL MIN() aggregate");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordMinutes:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new MinutesFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL MINUTES() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordMonth:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new MonthFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL MONTH() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordNow:
                    if (args.Count == 0)
                    {
                        sparqlFunc = new NowFunction();
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ABS() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordRegex:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new RegexFunction(args[0], args[1]);
                    }
                    else if (args.Count == 3)
                    {
                        sparqlFunc = new RegexFunction(args[0], args[1], args[2]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL REGEX() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordRound:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new RoundFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL ROUND() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSameTerm:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new SameTermFunction(args[0], args[1]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SAMETERM() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSample:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new AggregateTerm(new SampleAggregate(args.First()));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL AVG() aggregate");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSeconds:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new SecondsFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SECONDS() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSha1:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new Sha1HashFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SHA1() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSha256:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new Sha256HashFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SHA256() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSha384:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new Sha384HashFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SHA384() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSha512:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new Sha512HashFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SHA512() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordStr:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new StrFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL STR() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordStrDt:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new StrDtFunction(args[0], args[1]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL STRDT() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordStrEnds:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new StrEndsFunction(args[0], args[1]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL STRENDS() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordStrLang:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new StrLangFunction(args[0], args[1]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL STRLANG() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordStrLen:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new StrLenFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL STRKEN() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordStrStarts:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new StrStartsFunction(args[0], args[1]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL STRSTARTS() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSubStr:
                    if (args.Count == 2)
                    {
                        sparqlFunc = new SubStrFunction(args[0], args[1]);
                    }
                    else if (args.Count == 3)
                    {
                        sparqlFunc = new SubStrFunction(args[0], args[1], args[2]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SUBSTR() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordSum:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new AggregateTerm(new SumAggregate(args.First()));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL SUM() aggregate");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordTimezone:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new TimezoneFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL TIMEZONE() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordTz:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new TZFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL TZ() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordUCase:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new UCaseFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL UCASE() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordUri:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new IriFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL URI() function");
                    }
                    break;

                case SparqlSpecsHelper.SparqlKeywordYear:
                    if (args.Count == 1)
                    {
                        sparqlFunc = new YearFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the SPARQL YEAR() function");
                    }
                    break;
                }

                if (sparqlFunc != null)
                {
                    expr = sparqlFunc;
                    return(true);
                }
            }
            expr = null;
            return(false);
        }
コード例 #2
0
        /// <summary>
        /// Tries to create an Leviathan Function expression if the function Uri correseponds to a supported Leviathan Function
        /// </summary>
        /// <param name="u">Function Uri</param>
        /// <param name="args">Function Arguments</param>
        /// <param name="scalarArgs">Scalar Arguments</param>
        /// <param name="expr">Generated Expression</param>
        /// <returns>Whether an expression was successfully generated</returns>
        public bool TryCreateExpression(Uri u, List <ISparqlExpression> args, Dictionary <String, ISparqlExpression> scalarArgs, out ISparqlExpression expr)
        {
            // If any Scalar Arguments are present then can't possibly be a Leviathan Function
            if (scalarArgs.Count > 0)
            {
                expr = null;
                return(false);
            }

            String func = u.ToString();

            if (func.StartsWith(LeviathanFunctionsNamespace))
            {
                func = func.Substring(LeviathanFunctionsNamespace.Length);
                ISparqlExpression lvnFunc = null;

                switch (func)
                {
                case All:
                    if (args.Count == 1)
                    {
                        lvnFunc = new AggregateTerm(new AllAggregate(args.First()));
                    }
                    else if (args.Count == 2 && args.First() is DistinctModifier)
                    {
                        lvnFunc = new AggregateTerm(new AllAggregate(args.Last(), true));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for Leviathan all() aggregate");
                    }
                    break;

                case Any:
                    if (args.Count == 1)
                    {
                        lvnFunc = new AggregateTerm(new AnyAggregate(args.First()));
                    }
                    else if (args.Count == 2 && args.First() is DistinctModifier)
                    {
                        lvnFunc = new AggregateTerm(new AnyAggregate(args.Last(), true));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for Leviathan any() aggregate");
                    }
                    break;

                case Cartesian:
                    if (args.Count == 4)
                    {
                        lvnFunc = new CartesianFunction(args[0], args[1], args[2], args[3]);
                    }
                    else if (args.Count == 6)
                    {
                        lvnFunc = new CartesianFunction(args[0], args[1], args[2], args[3], args[4], args[5]);
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for Leviathan cartesian() function");
                    }
                    break;

                case Cube:
                    if (args.Count == 1)
                    {
                        lvnFunc = new CubeFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan cube() function");
                    }
                    break;

                case DegreesToRadians:
                    if (args.Count == 1)
                    {
                        lvnFunc = new DegreesToRadiansFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan degrees-to-radians() function");
                    }
                    break;

                case E:
                    if (args.Count == 1)
                    {
                        lvnFunc = new EFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan e() function");
                    }
                    break;

                case Factorial:
                    if (args.Count == 1)
                    {
                        lvnFunc = new FactorialFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan factorial() function");
                    }
                    break;

                case Ln:
                    if (args.Count == 1)
                    {
                        lvnFunc = new LeviathanNaturalLogFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan ln() function");
                    }
                    break;

                case Log:
                    if (args.Count == 1)
                    {
                        lvnFunc = new LogFunction(args.First());
                    }
                    else if (args.Count == 2)
                    {
                        lvnFunc = new LogFunction(args.First(), args.Last());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan log() function");
                    }
                    break;

                case MD5Hash:
                    if (args.Count == 1)
                    {
                        lvnFunc = new MD5HashFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan md5hash() function");
                    }
                    break;

                case Median:
                    if (args.Count == 1)
                    {
                        lvnFunc = new AggregateTerm(new MedianAggregate(args.First()));
                    }
                    else if (args.Count == 2 && args.First() is DistinctModifier)
                    {
                        lvnFunc = new AggregateTerm(new MedianAggregate(args.Last(), true));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan median() aggregate");
                    }
                    break;

                case Mode:
                    if (args.Count == 1)
                    {
                        lvnFunc = new AggregateTerm(new ModeAggregate(args.First()));
                    }
                    else if (args.Count == 2 && args.First() is DistinctModifier)
                    {
                        lvnFunc = new AggregateTerm(new ModeAggregate(args.Last(), true));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan mode() aggregate");
                    }
                    break;

                case None:
                    if (args.Count == 1)
                    {
                        lvnFunc = new AggregateTerm(new NoneAggregate(args.First()));
                    }
                    else if (args.Count == 2 && args.First() is DistinctModifier)
                    {
                        lvnFunc = new AggregateTerm(new NoneAggregate(args.Last(), true));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan none() aggregate");
                    }
                    break;

                case NumericMax:
                    if (args.Count == 1)
                    {
                        lvnFunc = new AggregateTerm(new NumericMaxAggregate(args.First()));
                    }
                    else if (args.Count == 2 && args.First() is DistinctModifier)
                    {
                        lvnFunc = new AggregateTerm(new NumericMaxAggregate(args.Last(), true));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan nmax() aggregate");
                    }
                    break;

                case NumericMin:
                    if (args.Count == 1)
                    {
                        lvnFunc = new AggregateTerm(new NumericMinAggregate(args.First()));
                    }
                    else if (args.Count == 2 && args.First() is DistinctModifier)
                    {
                        lvnFunc = new AggregateTerm(new NumericMinAggregate(args.Last(), true));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan nmin() aggregate");
                    }
                    break;

                case Power:
                    if (args.Count == 1)
                    {
                        lvnFunc = new SquareFunction(args.First());
                    }
                    else if (args.Count == 2)
                    {
                        lvnFunc = new PowerFunction(args.First(), args.Last());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan pow() function");
                    }
                    break;

                case Pythagoras:
                    if (args.Count == 2)
                    {
                        lvnFunc = new PythagoreanDistanceFunction(args.First(), args.Last());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan pythagoras() function");
                    }
                    break;

                case RadiansToDegrees:
                    if (args.Count == 1)
                    {
                        lvnFunc = new RadiansToDegreesFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan radians-to-degrees() function");
                    }
                    break;

                case Random:
                    if (args.Count == 0)
                    {
                        lvnFunc = new RandomFunction();
                    }
                    else if (args.Count == 1)
                    {
                        lvnFunc = new RandomFunction(args.First());
                    }
                    else if (args.Count == 2)
                    {
                        lvnFunc = new RandomFunction(args.First(), args.Last());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan rnd() function");
                    }
                    break;

                case Reciprocal:
                    if (args.Count == 1)
                    {
                        lvnFunc = new ReciprocalFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan reciprocal() function");
                    }
                    break;

                case Root:
                    if (args.Count == 1)
                    {
                        lvnFunc = new SquareRootFunction(args.First());
                    }
                    else if (args.Count == 2)
                    {
                        lvnFunc = new RootFunction(args.First(), args.Last());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan root() function");
                    }
                    break;

                case Sha256Hash:
                    if (args.Count == 1)
                    {
                        lvnFunc = new Sha256HashFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan sha256hash() function");
                    }
                    break;

                case Square:
                    if (args.Count == 1)
                    {
                        lvnFunc = new SquareFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan sq() function");
                    }
                    break;

                case SquareRoot:
                    if (args.Count == 1)
                    {
                        lvnFunc = new SquareRootFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan sqrt() function");
                    }
                    break;

                case Ten:
                    if (args.Count == 1)
                    {
                        lvnFunc = new TenFunction(args.First());
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan ten() function");
                    }
                    break;

                case TrigCos:
                case TrigCosInv:
                    if (args.Count == 1)
                    {
                        lvnFunc = new CosineFunction(args.First(), func.Equals(TrigCosInv));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan " + func + "() function");
                    }
                    break;

                case TrigCosec:
                case TrigCosecInv:
                    if (args.Count == 1)
                    {
                        lvnFunc = new CosecantFunction(args.First(), func.Equals(TrigCosecInv));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan " + func + "() function");
                    }
                    break;

                case TrigCotan:
                case TrigCotanInv:
                    if (args.Count == 1)
                    {
                        lvnFunc = new CotangentFunction(args.First(), func.Equals(TrigCotanInv));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan " + func + "() function");
                    }
                    break;

                case TrigSec:
                case TrigSecInv:
                    if (args.Count == 1)
                    {
                        lvnFunc = new SecantFunction(args.First(), func.Equals(TrigSecInv));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan " + func + "() function");
                    }
                    break;

                case TrigSin:
                case TrigSinInv:
                    if (args.Count == 1)
                    {
                        lvnFunc = new SineFunction(args.First(), func.Equals(TrigSinInv));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan " + func + "() function");
                    }
                    break;

                case TrigTan:
                case TrigTanInv:
                    if (args.Count == 1)
                    {
                        lvnFunc = new TangentFunction(args.First(), func.Equals(TrigTanInv));
                    }
                    else
                    {
                        throw new RdfParseException("Incorrect number of arguments for the Leviathan " + func + "() function");
                    }
                    break;
                }

                if (lvnFunc != null)
                {
                    expr = lvnFunc;
                    return(true);
                }
            }
            expr = null;
            return(false);
        }