private void LoadTables(GrammarReader reader)
{
Object obj; Int16 index;
while (reader.MoveNext())
{
byte id = (byte)reader.RetrieveNext();
switch ((RecordId)id)
{
case RecordId.Parameters:
m_parameters["Name"] = (String)reader.RetrieveNext();
m_parameters["Version"] = (String)reader.RetrieveNext();
m_parameters["Author"] = (String)reader.RetrieveNext();
m_parameters["About"] = (String)reader.RetrieveNext();
m_caseSensitive = (Boolean)reader.RetrieveNext();
m_startSymbol = (Int16)reader.RetrieveNext();
break;
case RecordId.TableCounts:
m_symbols = new Symbol[(Int16)reader.RetrieveNext()];
m_charsets = new String[(Int16)reader.RetrieveNext()];
m_rules = new Rule[(Int16)reader.RetrieveNext()];
m_DfaStates = new FAState[(Int16)reader.RetrieveNext()];
m_LalrTables = new LRActionTable[(Int16)reader.RetrieveNext()];
m_initialized = true;
break;
case RecordId.Initial:
m_initDfaState = (Int16)reader.RetrieveNext();
m_initLalrState = (Int16)reader.RetrieveNext();
break;
case RecordId.Symbols:
index = (Int16)reader.RetrieveNext();
String name = (String)reader.RetrieveNext();
SymbolType kind = (SymbolType)(Int16)reader.RetrieveNext();
Symbol symbol = new Symbol(index, name, kind);
AddSymbol(symbol);
break;
case RecordId.CharSets:
index = (Int16)reader.RetrieveNext();
String charset = (String)reader.RetrieveNext();
AddCharset(index, charset);
break;
case RecordId.Rules:
index = (Int16)reader.RetrieveNext();
Symbol head = m_symbols[(Int16)reader.RetrieveNext()];
Rule rule = new Rule(index, head);
reader.RetrieveNext(); // reserved
while ((obj = reader.RetrieveNext()) != null)
rule.AddItem(m_symbols[(Int16)obj]);
AddRule(rule);
break;
case RecordId.DFAStates:
FAState fastate = new FAState();
index = (Int16)reader.RetrieveNext();
if ((bool)reader.RetrieveNext())
fastate.AcceptSymbol = (Int16)reader.RetrieveNext();
else
reader.RetrieveNext();
reader.RetrieveNext(); // reserverd
while (! reader.RetrieveDone())
{
Int16 ci = (Int16)reader.RetrieveNext();
Int16 ti = (Int16)reader.RetrieveNext();
reader.RetrieveNext(); // reserved
fastate.AddEdge(m_charsets[ci], ti);
}
AddDfaState(index, fastate);
break;
case RecordId.LRTables:
LRActionTable table = new LRActionTable();
index = (Int16)reader.RetrieveNext();
reader.RetrieveNext(); // reserverd
while (! reader.RetrieveDone())
{
Int16 sid = (Int16)reader.RetrieveNext();
Int16 action = (Int16)reader.RetrieveNext();
Int16 tid = (Int16)reader.RetrieveNext();
reader.RetrieveNext(); // reserved
table.AddItem(m_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");
}
}
}
/// <summary>Produces a reduction.</summary>
/// <remarks>Removes as many tokens as members in the rule and pushes a
/// non-terminal token.</remarks>
private ParseResult Reduce(Rule p_rule)
{
ParseResult result;
Token head;
if (m_trimReductions && p_rule.ContainsOneNonTerminal)
{
// The current rule only consists of a single nonterminal and can be trimmed from the
// parse tree. Usually we create a new Reduction, assign it to the Data property
// of Head and push it on the stack. However, in this case, the Data property of the
// Head will be assigned the Data property of the reduced token (i.e. the only one
// on the stack). In this case, to save code, the value popped of the stack is changed
// into the head.
head = m_tempStack.PopToken();
head.SetParent(p_rule.RuleNonTerminal);
result = ParseResult.ReduceEliminated;
}
else
{
Reduction reduction = new Reduction();
reduction.ParentRule = p_rule;
m_tempStack.PopTokensInto(reduction, p_rule.SymbolCount);
head = new Token();
head.Data = reduction;
head.SetParent(p_rule.RuleNonTerminal);
m_haveReduction = true;
result = ParseResult.ReduceNormal;
}
int index = m_tempStack.PeekToken().State;
LRAction action = m_LalrTables[index].GetActionForSymbol(p_rule.RuleNonTerminal.TableIndex);
if (action != null)
{
head.State = m_LalrState = action.Value;;
m_tempStack.PushToken(head);
}
else
throw new ParserException("Action for LALR state is null");
return result;
}
private void AddRule(Rule p_rule)
{
if (! m_initialized)
throw new ParserException("Table sizes not initialized");
int index = p_rule.TableIndex;
m_rules[index] = p_rule;
}