private IToken TryParseObject(ITokenQueue tokens)
{
IToken next = tokens.Dequeue();
switch (next.TokenType)
{
case Token.BLANKNODEWITHID:
case Token.LITERALWITHDT:
case Token.LITERALWITHLANG:
case Token.URI:
//OK
return(next);
case Token.LITERAL:
//Check for Datatype/Language
IToken temp = tokens.Peek();
if (temp.TokenType == Token.DATATYPE)
{
tokens.Dequeue();
return(new LiteralWithDataTypeToken(next, (DataTypeToken)temp));
}
else if (temp.TokenType == Token.LANGSPEC)
{
tokens.Dequeue();
return(new LiteralWithLanguageSpecifierToken(next, (LanguageSpecifierToken)temp));
}
else
{
return(next);
}
default:
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Blank Node/Literal/URI as the Object of a Triple", next);
}
}
private void Parse(IRdfHandler handler, ITokenQueue tokens)
{
IToken next;
IToken s, p, o;
try
{
handler.StartRdf();
//Expect a BOF token at start
next = tokens.Dequeue();
if (next.TokenType != Token.BOF)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a BOF token at the start of the input", next);
}
do
{
next = tokens.Peek();
if (next.TokenType == Token.EOF)
{
return;
}
s = this.TryParseSubject(tokens);
p = this.TryParsePredicate(tokens);
o = this.TryParseObject(tokens);
Uri context = this.TryParseContext(tokens);
this.TryParseTriple(handler, s, p, o, context);
next = tokens.Peek();
} while (next.TokenType != Token.EOF);
handler.EndRdf(true);
}
catch (RdfParsingTerminatedException)
{
handler.EndRdf(true);
//Discard this - it justs means the Handler told us to stop
}
catch
{
handler.EndRdf(false);
throw;
}
}
private Uri TryParseContext(ITokenQueue tokens)
{
IToken next = tokens.Dequeue();
if (next.TokenType == Token.DOT)
{
return null;
}
else
{
INode context;
switch (next.TokenType)
{
case Token.BLANKNODEWITHID:
context = new BlankNode(null, next.Value.Substring(2));
break;
case Token.URI:
context = new UriNode(null, new Uri(next.Value));
break;
case Token.LITERAL:
//Check for Datatype/Language
IToken temp = tokens.Peek();
if (temp.TokenType == Token.LANGSPEC)
{
tokens.Dequeue();
context = new LiteralNode(null, next.Value, temp.Value);
}
else if (temp.TokenType == Token.DATATYPE)
{
tokens.Dequeue();
context = new LiteralNode(null, next.Value, new Uri(temp.Value.Substring(1, temp.Value.Length - 2)));
}
else
{
context = new LiteralNode(null, next.Value);
}
break;
default:
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Blank Node/Literal/URI as the Context of the Triple", next);
}
//Ensure we then see a . to terminate the Quad
next = tokens.Dequeue();
if (next.TokenType != Token.DOT)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Dot Token (Line Terminator) to terminate a Triple", next);
}
//Finally return the Context URI
if (context.NodeType == NodeType.Uri)
{
return ((IUriNode)context).Uri;
}
else if (context.NodeType == NodeType.Blank)
{
return new Uri("nquads:bnode:" + context.GetHashCode());
}
else if (context.NodeType == NodeType.Literal)
{
return new Uri("nquads:literal:" + context.GetHashCode());
}
else
{
throw ParserHelper.Error("Cannot turn a Node of type '" + context.GetType().ToString() + "' into a Context URI for a Triple", next);
}
}
}
private IToken TryParseObject(ITokenQueue tokens)
{
IToken next = tokens.Dequeue();
switch (next.TokenType)
{
case Token.BLANKNODEWITHID:
case Token.LITERALWITHDT:
case Token.LITERALWITHLANG:
case Token.URI:
//OK
return next;
case Token.LITERAL:
//Check for Datatype/Language
IToken temp = tokens.Peek();
if (temp.TokenType == Token.DATATYPE)
{
tokens.Dequeue();
return new LiteralWithDataTypeToken(next, (DataTypeToken)temp);
}
else if (temp.TokenType == Token.LANGSPEC)
{
tokens.Dequeue();
return new LiteralWithLanguageSpecifierToken(next, (LanguageSpecifierToken)temp);
}
else
{
return next;
}
default:
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Blank Node/Literal/URI as the Object of a Triple", next);
}
}
private void Parse(IRdfHandler handler, ITokenQueue tokens)
{
IToken next;
IToken s, p, o;
try
{
handler.StartRdf();
//Expect a BOF token at start
next = tokens.Dequeue();
if (next.TokenType != Token.BOF)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a BOF token at the start of the input", next);
}
do
{
next = tokens.Peek();
if (next.TokenType == Token.EOF) return;
s = this.TryParseSubject(tokens);
p = this.TryParsePredicate(tokens);
o = this.TryParseObject(tokens);
Uri context = this.TryParseContext(tokens);
this.TryParseTriple(handler, s, p, o, context);
next = tokens.Peek();
} while (next.TokenType != Token.EOF);
handler.EndRdf(true);
}
catch (RdfParsingTerminatedException)
{
handler.EndRdf(true);
//Discard this - it justs means the Handler told us to stop
}
catch
{
handler.EndRdf(false);
throw;
}
}
private Uri TryParseContext(ITokenQueue tokens)
{
IToken next = tokens.Dequeue();
if (next.TokenType == Token.DOT)
{
return(null);
}
else
{
INode context;
switch (next.TokenType)
{
case Token.BLANKNODEWITHID:
context = new BlankNode(null, next.Value.Substring(2));
break;
case Token.URI:
context = new UriNode(null, new Uri(next.Value));
break;
case Token.LITERAL:
//Check for Datatype/Language
IToken temp = tokens.Peek();
if (temp.TokenType == Token.LANGSPEC)
{
tokens.Dequeue();
context = new LiteralNode(null, next.Value, temp.Value);
}
else if (temp.TokenType == Token.DATATYPE)
{
tokens.Dequeue();
context = new LiteralNode(null, next.Value, new Uri(temp.Value.Substring(1, temp.Value.Length - 2)));
}
else
{
context = new LiteralNode(null, next.Value);
}
break;
default:
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Blank Node/Literal/URI as the Context of the Triple", next);
}
//Ensure we then see a . to terminate the Quad
next = tokens.Dequeue();
if (next.TokenType != Token.DOT)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Dot Token (Line Terminator) to terminate a Triple", next);
}
//Finally return the Context URI
if (context.NodeType == NodeType.Uri)
{
return(((IUriNode)context).Uri);
}
else if (context.NodeType == NodeType.Blank)
{
return(new Uri("nquads:bnode:" + context.GetHashCode()));
}
else if (context.NodeType == NodeType.Literal)
{
return(new Uri("nquads:literal:" + context.GetHashCode()));
}
else
{
throw ParserHelper.Error("Cannot turn a Node of type '" + context.GetType().ToString() + "' into a Context URI for a Triple", next);
}
}
}
private Uri TryParseContext(IRdfHandler handler, ITokenQueue tokens)
{
IToken next = tokens.Dequeue();
if (next.TokenType == Token.DOT)
{
return(null);
}
INode context;
switch (next.TokenType)
{
case Token.BLANKNODEWITHID:
context = handler.CreateBlankNode(next.Value.Substring(2));
break;
case Token.URI:
context = TryParseUri(handler, next.Value);
break;
case Token.LITERAL:
if (this.Syntax != NQuadsSyntax.Original)
{
throw new RdfParseException("Only a Blank Node/URI may be used as the graph name in RDF NQuads 1.1");
}
//Check for Datatype/Language
IToken temp = tokens.Peek();
switch (temp.TokenType)
{
case Token.LANGSPEC:
tokens.Dequeue();
context = handler.CreateLiteralNode(next.Value, temp.Value);
break;
case Token.DATATYPE:
tokens.Dequeue();
context = handler.CreateLiteralNode(next.Value, ((IUriNode)TryParseUri(handler, temp.Value.Substring(1, temp.Value.Length - 2))).Uri);
break;
default:
context = handler.CreateLiteralNode(next.Value);
break;
}
break;
default:
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Blank Node/Literal/URI as the Context of the Triple", next);
}
//Ensure we then see a . to terminate the Quad
next = tokens.Dequeue();
if (next.TokenType != Token.DOT)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a Dot Token (Line Terminator) to terminate a Triple", next);
}
//Finally return the Context URI
if (context.NodeType == NodeType.Uri)
{
return(((IUriNode)context).Uri);
}
else if (context.NodeType == NodeType.Blank)
{
return(UriFactory.Create("nquads:bnode:" + context.GetHashCode()));
}
else if (context.NodeType == NodeType.Literal)
{
return(UriFactory.Create("nquads:literal:" + context.GetHashCode()));
}
else
{
throw ParserHelper.Error("Cannot turn a Node of type '" + context.GetType().ToString() + "' into a Context URI for a Triple", next);
}
}