/// <summary>
/// Adds a Variable to the Query
/// </summary>
/// <param name="var">Variable</param>
protected internal void AddVariable(SparqlVariable var)
{
if (!this._vars.ContainsKey(var.Name))
{
this._vars.Add(var.Name, var);
}
else
{
throw new RdfQueryException("Variable ?" + var.Name + " is already defined in this Query");
}
}
/// <summary>
/// Adds a Variable to the Query
/// </summary>
/// <param name="var">Variable</param>
protected internal void AddVariable(SparqlVariable var)
{
if (!this._vars.Any(v => v.Name.Equals(var)))
{
this._vars.Add(var);
}
else
{
throw new RdfQueryException("Variable ?" + var.Name + " is already defined in this Query");
}
}
public void SparqlVarNames()
{
List <String> names = new List <String>
{
"?var",
"$var",
"var"
};
foreach (String name in names)
{
SparqlVariable var = new SparqlVariable(name);
Assert.AreEqual("var", var.Name);
VariablePattern varPat = new VariablePattern(name);
Assert.AreEqual("var", varPat.VariableName);
VariableTerm varTerm = new VariableTerm(name);
Assert.AreEqual("var", varTerm.Variables.First());
}
}
public void SparqlVarNames()
{
var names = new List <string>
{
"?var",
"$var",
"var"
};
foreach (var name in names)
{
var var = new SparqlVariable(name);
Assert.Equal("var", var.Name);
var varPat = new VariablePattern(name);
Assert.Equal("var", varPat.VariableName);
var varTerm = new VariableTerm(name);
Assert.Equal("var", varTerm.Variables.First());
}
}
/// <summary>
/// Adds a Variable to the Query
/// </summary>
/// <param name="var">Variable</param>
protected internal void AddVariable(SparqlVariable var)
{
if (!this._vars.ContainsKey(var.Name))
{
this._vars.Add(var.Name, var);
}
else
{
throw new RdfQueryException("Variable ?" + var.Name + " is already defined in this Query");
}
}
private SparqlVariable TryParseAggregate(SparqlQueryParserContext context, IToken agg)
{
if (context.SyntaxMode == SparqlQuerySyntax.Sparql_1_0) throw ParserHelper.Error("Aggregates are not supported in SPARQL 1.0", agg);
IToken next;
SparqlVariable var;
ISparqlAggregate aggregate;
//Check that the Token is an Aggregate Keyword Token
switch (agg.TokenType)
{
case Token.AVG:
case Token.COUNT:
case Token.GROUPCONCAT:
case Token.MAX:
case Token.MEDIAN:
case Token.MIN:
case Token.MODE:
case Token.NMAX:
case Token.NMIN:
case Token.SAMPLE:
case Token.SUM:
//OK
break;
default:
throw ParserHelper.Error("Cannot parse an Aggregate since '" + agg.GetType().ToString() + "' is not an Aggregate Keyword Token", agg);
}
//Gather up the Tokens and call into the Expression Parser to get this parsed
Queue<IToken> tokens = new Queue<IToken>();
tokens.Enqueue(agg);
int openBrackets = 0;
do
{
next = context.Tokens.Dequeue();
if (next.TokenType == Token.LEFTBRACKET)
{
openBrackets++;
}
else if (next.TokenType == Token.RIGHTBRACKET)
{
openBrackets--;
}
tokens.Enqueue(next);
} while (openBrackets > 0);
context.ExpressionParser.AllowAggregates = true;
ISparqlExpression aggExpr = context.ExpressionParser.Parse(tokens);
context.ExpressionParser.AllowAggregates = false;
if (aggExpr is AggregateExpressionTerm)
{
aggregate = ((AggregateExpressionTerm)aggExpr).Aggregate;
}
else if (aggExpr is NonNumericAggregateExpressionTerm)
{
aggregate = ((NonNumericAggregateExpressionTerm)aggExpr).Aggregate;
}
else
{
throw new RdfParseException("Unexpected expression was parsed when an Aggregate was expected: " + aggExpr.ToString());
}
//See if there is an alias
String alias = "Result";
next = context.Tokens.Peek();
if (next.TokenType == Token.AS)
{
context.Tokens.Dequeue();
next = context.Tokens.Dequeue();
if (next.TokenType != Token.VARIABLE)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "', expected a Variable Token after an AS Keyword to act as an aliased name for the Aggregate", next);
}
alias = next.Value.Substring(1);
}
else
{
if (context.SyntaxMode != SparqlQuerySyntax.Extended) throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected an AS keyword after an Aggregate", next);
int nextID = context.NextAliasID;
if (nextID > 0) alias += nextID.ToString();
while (context.Query.Variables.Any(v => v.Name.Equals(alias)))
{
alias = "Result" + context.NextAliasID;
}
this.RaiseWarning("No AS ?variable given for the Aggregate " + aggregate.ToString() + " so assigning alias '" + alias + "'");
}
var = new SparqlVariable(alias, aggregate);
return var;
}
