/// <summary>
/// Adds inline data to a Graph Pattern respecting any BGP breaks
/// </summary>
/// <param name="data"></param>
internal void AddInlineData(BindingsPattern data)
{
if (_break)
{
if (_broken)
{
_graphPatterns.Last().AddInlineData(data);
}
else if (_data == null && _graphPatterns.Count == 0)
{
_data = data;
}
else
{
GraphPattern p = new GraphPattern();
p.AddInlineData(data);
_graphPatterns.Add(p);
}
}
else if (_isUnion)
{
BreakBGP();
AddInlineData(data);
}
else
{
_data = data;
BreakBGP();
}
}
/// <summary>
/// Adds inline data to a Graph Pattern respecting any BGP breaks
/// </summary>
/// <param name="data"></param>
internal void AddInlineData(BindingsPattern data)
{
if (this._break)
{
if (this._broken)
{
this._graphPatterns.Last().AddInlineData(data);
}
else if (this._data == null && this._graphPatterns.Count == 0)
{
this._data = data;
}
else
{
GraphPattern p = new GraphPattern();
p.AddInlineData(data);
this._graphPatterns.Add(p);
}
}
else if (this._isUnion)
{
this.BreakBGP();
this.AddInlineData(data);
}
else
{
this._data = data;
this.BreakBGP();
}
}
/// <summary>
/// Creates a new BINDINGS modifier
/// </summary>
/// <param name="bindings">Bindings</param>
/// <param name="pattern">Pattern</param>
public Bindings(BindingsPattern bindings, ISparqlAlgebra pattern)
{
this._bindings = bindings;
this._pattern = pattern;
}
private void TryParseBindingsClause(SparqlQueryParserContext context)
{
//First expect one/more variables
IToken next = context.Tokens.Peek();
List<String> vars = new List<String>();
while (next.TokenType == Token.VARIABLE)
{
vars.Add(next.Value.Substring(1));
context.Tokens.Dequeue();
next = context.Tokens.Peek();
}
if (vars.Count == 0)
{
//If No Variables then expect an empty BINDINGS { }
next = context.Tokens.Peek();
if (next.TokenType != Token.LEFTCURLYBRACKET)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected either one/more Variable Tokens or the empty set { } after a BINDINGS keyword", next);
}
}
//Then expect a Left Curly Bracket
if (next.TokenType == Token.LEFTCURLYBRACKET)
{
context.Tokens.Dequeue();
BindingsPattern bindings = new BindingsPattern(vars);
//Each Binding tuple must start with a (
next = context.Tokens.Peek();
while (next.TokenType == Token.LEFTBRACKET)
{
//Discard the ( and peek the next token
context.Tokens.Dequeue();
next = context.Tokens.Peek();
//Expect a sequence of values in the tuple
List<PatternItem> values = new List<PatternItem>();
while (next.TokenType != Token.RIGHTBRACKET)
{
next = context.Tokens.Dequeue();
//Get the value
switch (next.TokenType)
{
case Token.URI:
case Token.QNAME:
case Token.LITERALWITHDT:
case Token.LITERALWITHLANG:
case Token.PLAINLITERAL:
values.Add(this.TryCreatePatternItem(context, next));
break;
case Token.LONGLITERAL:
case Token.LITERAL:
//Need to check for subsequent datatype or language declaration
IToken lit = next;
next = context.Tokens.Peek();
if (next.TokenType == Token.HATHAT)
{
context.Tokens.Dequeue();
next = context.Tokens.Dequeue();
if (next.TokenType == Token.DATATYPE)
{
LiteralWithDataTypeToken dtlit = new LiteralWithDataTypeToken(lit, (DataTypeToken)next);
values.Add(this.TryCreatePatternItem(context, dtlit));
}
else
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Datatype Token to specify the datatype for a Literal", next);
}
}
else if (next.TokenType == Token.LANGSPEC)
{
context.Tokens.Dequeue();
LiteralWithLanguageSpecifierToken langlit = new LiteralWithLanguageSpecifierToken(lit, (LanguageSpecifierToken)next);
values.Add(this.TryCreatePatternItem(context, langlit));
}
else
{
values.Add(this.TryCreatePatternItem(context, lit));
}
break;
case Token.UNDEF:
//UNDEF indicates an unbound variable which equates to a null
values.Add(null);
break;
default:
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Token for a URI/Literal or an UNDEF keyword as part of a tuple in a BINDINGS clause", next);
}
next = context.Tokens.Peek();
}
if (vars.Count != values.Count)
{
throw new RdfParseException("Invalid tuple in the BINDINGS clause, each Binding should contain " + vars.Count + " values but got a tuple containing " + values.Count + " values");
}
//Generate a representation of this possible solution and add it to our Bindings object
bindings.AddTuple(new BindingTuple(vars, values));
//Discard the ) and peek the next token
context.Tokens.Dequeue();
next = context.Tokens.Peek();
}
//Set the Query's BINDINGS clause
context.Query.Bindings = bindings;
//Finally we need to see a Right Curly Bracket
if (next.TokenType != Token.RIGHTCURLYBRACKET)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Right Curly Bracket to terminate the BINDINGS clause", next);
}
context.Tokens.Dequeue();
}
else
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Left Curly Bracket after the list of variables as part of a BINDINGS clause", next);
}
}
