/// <summary>
/// Reads a CGT and creates all the objects needed to create
/// a tokenizer and parser at a later time.
/// </summary>
/// <param name="stream">The CGT stream.</param>
private void ReadFile(Stream stream)
{
try
{
Reset();
this.stream = stream;
CalithaBinReader reader = new CalithaBinReader(stream);
string header = "";
try
{
header = reader.ReadUnicodeString();
if (!header.StartsWith("GOLD"))
{
throw new CGTStructureException("File header is invalid");
}
}
catch (EndOfStreamException e)
{
throw new CGTStructureException("File header is invalid", e);
}
RecordCollection records = new RecordCollection();
while (!(stream.Position == stream.Length))
{
records.Add(ReadRecord(reader));
}
structure = new CGTStructure(header, records);
content = new CGTContent(structure);
dfaStates = CreateDFAStates(content);
parserStates = CreateParserStates(content);
}
finally
{
stream.Close();
}
}
private DFA.StateCollection CreateDFAStates(CGTContent content)
{
symbols = CreateSymbols(content);
DFA.StateCollection states = new DFA.StateCollection();
foreach (DFAStateRecord stateRecord in content.DFAStateTable)
{
DFA.State state;
if (stateRecord.AcceptState)
{
Symbol symbol = symbols[stateRecord.AcceptIndex];
state = new DFA.EndState(stateRecord.Index, (SymbolTerminal)symbol);
//todo: type checking (exception?)
}
else
{
state = new DFA.State(stateRecord.Index);
}
states.Add(state);
}
foreach (DFAStateRecord stateRecord in content.DFAStateTable)
{
foreach (EdgeSubRecord edgeRecord in stateRecord.EdgeSubRecords)
{
DFA.State source = states[stateRecord.Index];
DFA.State target = states[edgeRecord.TargetIndex];
CharacterSetRecord charsetRec = content.CharacterSetTable[edgeRecord.CharacterSetIndex];
DFA.Transition transition = new DFA.Transition(target, charsetRec.Characters);
source.Transitions.Add(transition);
}
}
return(states);
}
private void Reset()
{
stream = null;
structure = null;
content = null;
dfaStates = null;
parserStates = null;
symbols = null;
rules = null;
}
/// <summary>
/// Creates a new DFA.
/// </summary>
/// <param name="states">The states that are part of the DFA.</param>
/// <param name="startState">The starting state</param>
public DFA(StateCollection states, State startState)
{
this.states = states;
this.startState = startState;
this.currentState = startState;
}