private object Parse(string txt)
{
lock (this)
{
object result = null;
txt = txt.Replace("\r\n", "\n") + "\n";
parser.Open(ref txt);
parser.TrimReductions = false;
bool done = false;
while (!done)
{
GOLD.ParseMessage response = parser.Parse();
switch (response)
{
case GOLD.ParseMessage.LexicalError:
case GOLD.ParseMessage.SyntaxError:
case GOLD.ParseMessage.InternalError:
case GOLD.ParseMessage.NotLoadedError:
case GOLD.ParseMessage.GroupError:
Fail(response);
break;
case GOLD.ParseMessage.Reduction: // Reduction
parser.CurrentReduction = GrammarTableMap.CreateNewASTObject(parser.CurrentReduction as GOLD.Reduction, parser.CurrentPosition());
break;
case GOLD.ParseMessage.Accept: //Accepted!
result = parser.CurrentReduction;
done = true;
break;
case GOLD.ParseMessage.TokenRead: //You don't have to do anything here.
break;
}
}
return(result);
}
}
private void Fail(GOLD.ParseMessage msg)
{
switch (msg)
{
case GOLD.ParseMessage.LexicalError: //Cannot recognize token
throw new LexicalErrorException(parser.CurrentToken().Data, new SourceCodePosition(parser));
case GOLD.ParseMessage.SyntaxError: //Expecting a different token
throw new SyntaxErrorException(parser.CurrentToken().Data, parser.ExpectedSymbols().Text(), new SourceCodePosition(parser));
case GOLD.ParseMessage.InternalError: //INTERNAL ERROR! Something is horribly wrong.
throw new InternalErrorException(new SourceCodePosition(parser));
case GOLD.ParseMessage.NotLoadedError: //This error occurs if the CGT was not loaded.
throw new NotLoadedErrorException(new SourceCodePosition(parser));
case GOLD.ParseMessage.GroupError: //GROUP ERROR! Unexpected end of file
throw new GroupErrorException(new SourceCodePosition(parser));
}
}
// Encapsulation of call to GOLD.Parser.Parse() and analysing callbacks from production building
public bool Parse(TextReader reader)
{
//This procedure starts the GOLD Parser Engine and handles each of the
//messages it returns. Each time a reduction is made, you can create new
//custom object and reassign the .CurrentReduction property. Otherwise,
//the system will use the Reduction object that was returned.
//
//The resulting tree will be a pure representation of the language
//and will be ready to implement.
bool done = false; //Controls when we leave the loop
bool accepted = false; //Was the parse successful?
m_coreParser.Open(reader);
m_coreParser.TrimReductions = false; //Please read about this feature before enabling
while (!done)
{
GOLD.ParseMessage response = m_coreParser.Parse();
switch (response)
{
case GOLD.ParseMessage.LexicalError:
//Cannot recognize token
OnLexicalError();
done = true;
break;
case GOLD.ParseMessage.SyntaxError:
//Expecting a different token
OnSyntaxError();
done = true;
break;
case GOLD.ParseMessage.Reduction:
OnReduction();
break;
case GOLD.ParseMessage.Accept:
//Accepted!
OnAccept();
done = true;
accepted = true;
break;
case GOLD.ParseMessage.TokenRead:
//You don't have to do anything here.
break;
case GOLD.ParseMessage.InternalError:
//INTERNAL ERROR! Something is horribly wrong.
OnInternalError();
done = true;
break;
case GOLD.ParseMessage.NotLoadedError:
//This error occurs if the CGT was not loaded.
OnNotLoadedError();
done = true;
break;
case GOLD.ParseMessage.GroupError:
//GROUP ERROR! Unexpected end of file
OnGroupError();
done = true;
break;
}
} // End of while
return(accepted);
} // End of method Parse()
