/// <summary>
/// Adiciona uma tabela de ação.
/// </summary>
/// <param name="index"></param>
/// <param name="table"></param>
private void AddLalrTable(int index, LRActionTable table)
{
if (!_initialized)
{
throw new ParserException("Table counts not initialized");
}
_LalrTables[index] = table;
}
/// <summary>
/// Executa parser para o token.
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
private ParseResult ParseToken(Token token)
{
ParseResult result = ParseResult.InternalError;
LRActionTable table = _LalrTables[_LalrState];
LRAction action = table.GetActionForSymbol(token.TableIndex);
if (action != null)
{
_haveReduction = false;
_outputTokens.Clear();
switch (action.Action)
{
case Action.Accept:
_haveReduction = true;
result = ParseResult.Accept;
break;
case Action.Shift:
token.State = _LalrState = action.Value;
_tempStack.PushToken(token);
result = ParseResult.Shift;
break;
case Action.Reduce:
result = Reduce(_rules[action.Value]);
break;
}
}
else
{
_outputTokens.Clear();
foreach (LRAction a in table.Members)
{
SymbolType kind = a.Symbol.Kind;
if (kind == SymbolType.Terminal || kind == SymbolType.End)
{
_outputTokens.PushToken(new Token(a.Symbol));
}
}
result = ParseResult.SyntaxError;
}
return(result);
}
/// <summary>
/// Carrega as tabelas da gramática.
/// </summary>
/// <param name="reader"></param>
private void LoadTables(GrammarReader reader)
{
object obj;
int index;
while (reader.MoveNext())
{
byte id = (byte)reader.RetrieveNext();
switch ((RecordId)id)
{
case RecordId.Parameters:
_parameters["Name"] = (string)reader.RetrieveNext();
_parameters["Version"] = (string)reader.RetrieveNext();
_parameters["Author"] = (string)reader.RetrieveNext();
_parameters["About"] = (string)reader.RetrieveNext();
_caseSensitive = (bool)reader.RetrieveNext();
_startSymbol = (int)reader.RetrieveNext();
break;
case RecordId.TableCounts:
_symbols = new Symbol[(int)reader.RetrieveNext()];
_charsets = new String[(int)reader.RetrieveNext()];
_rules = new Rule[(int)reader.RetrieveNext()];
_DfaStates = new FAState[(int)reader.RetrieveNext()];
_LalrTables = new LRActionTable[(int)reader.RetrieveNext()];
_initialized = true;
break;
case RecordId.Initial:
_initDfaState = (int)reader.RetrieveNext();
_initLalrState = (int)reader.RetrieveNext();
break;
case RecordId.Symbols:
index = (int)reader.RetrieveNext();
var name = (string)reader.RetrieveNext();
var kind = (SymbolType)(int)reader.RetrieveNext();
var symbol = new Symbol(index, name, kind);
AddSymbol(symbol);
break;
case RecordId.CharSets:
index = (int)reader.RetrieveNext();
var charset = (string)reader.RetrieveNext();
AddCharset(index, charset);
break;
case RecordId.Rules:
index = (int)reader.RetrieveNext();
var head = _symbols[(int)reader.RetrieveNext()];
var rule = new Rule(index, head);
reader.RetrieveNext();
while ((obj = reader.RetrieveNext()) != null)
{
rule.AddItem(_symbols[(int)obj]);
}
AddRule(rule);
break;
case RecordId.DFAStates:
FAState fastate = new FAState();
index = (int)reader.RetrieveNext();
if ((bool)reader.RetrieveNext())
{
fastate.AcceptSymbol = (int)reader.RetrieveNext();
}
else
{
reader.RetrieveNext();
}
reader.RetrieveNext();
while (!reader.RetrieveDone())
{
var ci = (int)reader.RetrieveNext();
var ti = (int)reader.RetrieveNext();
reader.RetrieveNext();
fastate.AddEdge(_charsets[ci], ti);
}
AddDfaState(index, fastate);
break;
case RecordId.LRTables:
LRActionTable table = new LRActionTable();
index = (int)reader.RetrieveNext();
reader.RetrieveNext();
while (!reader.RetrieveDone())
{
var sid = (int)reader.RetrieveNext();
var action = (int)reader.RetrieveNext();
var tid = (int)reader.RetrieveNext();
reader.RetrieveNext();
table.AddItem(_symbols[sid], (Action)action, tid);
}
AddLalrTable(index, table);
break;
case RecordId.Comment:
Console.WriteLine("Comment record encountered");
break;
default:
throw new ParserException("Wrong id for record");
}
}
}
