/// <summary>
/// Tries to create an ARQ Function expression if the function Uri correseponds to a supported ARQ 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 an ARQ Function
if (scalarArgs.Count > 0)
{
expr = null;
return(false);
}
String func = u.AbsoluteUri;
if (func.StartsWith(ArqFunctionsNamespace))
{
func = func.Substring(ArqFunctionsNamespace.Length);
ISparqlExpression arqFunc = null;
switch (func)
{
case BNode:
if (args.Count == 1)
{
arqFunc = new BNodeFunction(args.First());
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ bnode() function");
}
break;
case E:
if (args.Count == 0)
{
arqFunc = new EFunction();
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ e() function");
}
break;
case LocalName:
if (args.Count == 1)
{
arqFunc = new LocalNameFunction(args.First());
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ localname() function");
}
break;
case Max:
if (args.Count == 2)
{
arqFunc = new MaxFunction(args.First(), args.Last());
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ max() function");
}
break;
case Min:
if (args.Count == 2)
{
arqFunc = new MinFunction(args.First(), args.Last());
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ min() function");
}
break;
case Namespace:
if (args.Count == 1)
{
arqFunc = new NamespaceFunction(args.First());
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ namespace() function");
}
break;
case Now:
if (args.Count == 0)
{
arqFunc = new NowFunction();
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ now() function");
}
break;
case Pi:
if (args.Count == 0)
{
arqFunc = new PiFunction();
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ pi() function");
}
break;
case Sha1Sum:
if (args.Count == 1)
{
arqFunc = new Sha1Function(args.First());
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ sha1sum() function");
}
break;
case StrJoin:
if (args.Count >= 2)
{
arqFunc = new StringJoinFunction(args.First(), args.Skip(1));
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ strjoing() function");
}
break;
case Substr:
case Substring:
if (args.Count == 2)
{
arqFunc = new SubstringFunction(args.First(), args.Last());
}
else if (args.Count == 3)
{
arqFunc = new SubstringFunction(args.First(), args[1], args.Last());
}
else
{
throw new RdfParseException("Incorrect number of arguments for the ARQ " + func + "() function");
}
break;
}
if (arqFunc != null)
{
expr = arqFunc;
return(true);
}
}
expr = null;
return(false);
}
private static ISparqlExpression BuildFunctionExpression(SingleValueFunctionCallNode functionOperator)
{
var funcName = functionOperator.Name;
string[] funcNames = { "contains", "endswith", "startswith", "length", "tolower", "toupper",
"substring", "replace", "concat", "indexof", "trim", "year", "day","month", "hour", "minute",
"second", "now", "ceiling", "floor", "round", };
if (!funcNames.Contains(funcName))
{
throw new NotImplementedException($"Function {funcName} not implemented.");
}
if (funcName == "now") // NOW() in sparql does not work, will generate this now in .net instead.
{
ISparqlExpression exp = new NowFunction();
return((new UnaryExpressionFilter(exp)).Expression);
}
var parameter = functionOperator.Parameters.ElementAt(0);
ISparqlExpression valueTerm = null;
if (parameter.GetType() == typeof(SingleValuePropertyAccessNode))
{
valueTerm = new VariableTerm($"?{(parameter as SingleValuePropertyAccessNode).Property.Name}");
}
else if (parameter.GetType() == typeof(SingleValueFunctionCallNode))
{
valueTerm = BuildFunctionExpression(parameter as SingleValueFunctionCallNode);
}
if (funcName == "length")
{
return((new UnaryExpressionFilter(new StrLenFunction(valueTerm))).Expression);
}
else if (funcName == "tolower")
{
return((new UnaryExpressionFilter(new LCaseFunction(valueTerm))).Expression);
}
else if (funcName == "toupper")
{
return((new UnaryExpressionFilter(new UCaseFunction(valueTerm))).Expression);
}
else if (funcName == "year")
{
return((new UnaryExpressionFilter(new YearFunction(valueTerm))).Expression);
}
else if (funcName == "day")
{
return((new UnaryExpressionFilter(new DayFunction(valueTerm))).Expression);
}
else if (funcName == "month")
{
return((new UnaryExpressionFilter(new MonthFunction(valueTerm))).Expression);
}
else if (funcName == "hour")
{
return((new UnaryExpressionFilter(new HoursFunction(valueTerm))).Expression);
}
else if (funcName == "minute")
{
return((new UnaryExpressionFilter(new MinutesFunction(valueTerm))).Expression);
}
else if (funcName == "second")
{
return((new UnaryExpressionFilter(new SecondsFunction(valueTerm))).Expression);
}
else if (funcName == "ceiling")
{
return((new UnaryExpressionFilter(new CeilFunction(valueTerm))).Expression);
}
else if (funcName == "floor")
{
return((new UnaryExpressionFilter(new FloorFunction(valueTerm))).Expression);
}
else if (funcName == "round")
{
return((new UnaryExpressionFilter(new RoundFunction(valueTerm))).Expression);
}
else
{
var constant = functionOperator.Parameters.ElementAt(1) as ConstantNode;
ConstantTerm constantTerm = new ConstantTerm(CreateLiteralNode(constant));
if (funcName == "contains")
{
return((new UnaryExpressionFilter(new ContainsFunction(valueTerm, constantTerm))).Expression);
}
else if (funcName == "endswith")
{
return((new UnaryExpressionFilter(new StrEndsFunction(valueTerm, constantTerm))).Expression);
}
else if (funcName == "startswith")
{
return((new UnaryExpressionFilter(new StrStartsFunction(valueTerm, constantTerm))).Expression);
}
else if (funcName == "concat")
{
return((new UnaryExpressionFilter(new ConcatFunction(new List <ISparqlExpression> {
valueTerm, constantTerm
}))).Expression);
}
else if (funcName == "indexof")
{
throw new NotImplementedException("Sparql does not have counterpart of indexof function.");
}
else if (funcName == "trim")
{
throw new NotImplementedException("Sparql needs regex to do trim.");
}
else if (funcName == "substring")
{
if (functionOperator.Parameters.Count() > 2)
{
var constant2 = functionOperator.Parameters.ElementAt(2) as ConstantNode;
ConstantTerm constantTerm2 = new ConstantTerm(CreateLiteralNode(constant2));
return((new UnaryExpressionFilter(new SubStrFunction(valueTerm, constantTerm, constantTerm2))).Expression);
}
else
{
return((new UnaryExpressionFilter(new SubStrFunction(valueTerm, constantTerm))).Expression);
}
}
else if (funcName == "replace")
{
var constant2 = functionOperator.Parameters.ElementAt(2) as ConstantNode;
ConstantTerm constantTerm2 = new ConstantTerm(CreateLiteralNode(constant2));
return((new UnaryExpressionFilter(new ReplaceFunction(valueTerm, constantTerm, constantTerm2))).Expression);
}
}
return(null);
}
/// <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);
}
