/// <summary> /// Determines whether an expression is an Implicit Join Expression /// </summary> /// <param name="expr">Expression</param> /// <param name="lhsVar">LHS Variable</param> /// <param name="rhsVar">RHS Variable</param> /// <param name="equals">Whether the expression is an equals (true) or a same term (false)</param> /// <returns></returns> private bool IsImplicitJoinExpression(ISparqlExpression expr, out String lhsVar, out String rhsVar, out bool equals) { lhsVar = null; rhsVar = null; equals = false; ISparqlExpression lhs, rhs; if (expr is EqualsExpression) { EqualsExpression eq = (EqualsExpression)expr; lhs = eq.Arguments.First(); rhs = eq.Arguments.Last(); equals = true; } else if (expr is SameTermFunction) { SameTermFunction st = (SameTermFunction)expr; lhs = st.Arguments.First(); rhs = st.Arguments.Last(); } else { return(false); } if (lhs is VariableTerm && rhs is VariableTerm) { lhsVar = lhs.Variables.First(); rhsVar = rhs.Variables.First(); return(!lhsVar.Equals(rhsVar)); } else { return(false); } }
/// <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); }
/// <summary> /// Creates a call of the SAMETERM function with two expression parameters /// </summary> /// <param name="eb"></param> /// <param name="left">a SPARQL expression</param> /// <param name="right">a SPARQL expression</param> public static BooleanExpression SameTerm(this ExpressionBuilder eb, SparqlExpression left, SparqlExpression right) { var sameTerm = new SameTermFunction(left.Expression, right.Expression); return(new BooleanExpression(sameTerm)); }
/// <summary> /// Determines whether an expression is an Identity Expression /// </summary> /// <param name="expr">Expression</param> /// <param name="var">Variable</param> /// <param name="term">Term</param> /// <param name="equals">Whether it is an equals expression (true) or a same term expression (false)</param> /// <returns></returns> private bool IsIdentityExpression(ISparqlExpression expr, out String var, out INode term, out bool equals) { var = null; term = null; equals = false; ISparqlExpression lhs, rhs; if (expr is EqualsExpression) { equals = true; EqualsExpression eq = (EqualsExpression)expr; lhs = eq.Arguments.First(); rhs = eq.Arguments.Last(); } else if (expr is SameTermFunction) { SameTermFunction st = (SameTermFunction)expr; lhs = st.Arguments.First(); rhs = st.Arguments.Last(); } else { return(false); } if (lhs is VariableTerm) { if (rhs.GetType().Equals(_exprType)) { var = lhs.Variables.First(); term = rhs.Evaluate(null, 0); if (term.NodeType == NodeType.Uri) { return(true); } else { return(false); } } else { return(false); } } else if (lhs.GetType().Equals(_exprType)) { if (rhs is VariableTerm) { var = rhs.Variables.First(); term = lhs.Evaluate(null, 0); if (term.NodeType == NodeType.Uri) { return(true); } else { return(false); } } else { return(false); } } else { return(false); } }
public BooleanExpression SameTerm(SparqlExpression left, SparqlExpression right) { var sameTerm = new SameTermFunction(left.Expression, right.Expression); return(new BooleanExpression(sameTerm)); }