private void ComputeStates()
{
mItemsByIndex = new Dictionary <LalrItemSet, int>();
mStates = new List <LalrItemSet>();
mCurrentItems = new HashSet <LalrItemSet>();
mNextItems = new HashSet <LalrItemSet>();
mRecordedGotos = new Dictionary <Tuple <int, Symbol>, int>();
var initialState = new LalrItemSet(new LalrItem[] {
new LalrItem(mDatabase[NonterminalSymbol.StartingSymbol].First(), 0, TerminalSymbol.Eof)
});
//mStates.Add(initialState);
mStates.Add(initialState.Closure(mDatabase));
//mItemsByIndex.Add(mStates[0].ToCoreSet(), 0);
mItemsByIndex.Add(mStates[0], 0);
mCurrentItems.Add(mStates[0]);
while (mCurrentItems.Count != 0)
{
foreach (var iset in mCurrentItems)
{
Expand(iset);
}
mCurrentItems.Clear();
mCurrentItems.UnionWith(mNextItems);
mNextItems.Clear();
}
CreateTable();
}
private void Expand(LalrItemSet iset)
{
//var thisIndex = mItemsByIndex[iset.ToCoreSet()];
var thisIndex = mItemsByIndex[iset];
var performGoto = iset.Goto(mDatabase);
foreach (var item in performGoto)
{
//var cs = item.Value.ToCoreSet();
//if(mItemsByIndex.ContainsKey(cs)){
if (mItemsByIndex.ContainsKey(item.Value))
{
//var index = mItemsByIndex[cs];
var index = mItemsByIndex[item.Value];
//mStates[index] = LalrItemSet.Merge(mStates[index], item.Value);
mRecordedGotos.Add(Tuple.Create(thisIndex, item.Key), index);
}
else
{
mStates.Add(item.Value);
//mItemsByIndex.Add(cs, mStates.Count - 1);
mItemsByIndex.Add(item.Value, mStates.Count - 1);
mNextItems.Add(item.Value);
mRecordedGotos.Add(Tuple.Create(thisIndex, item.Key), mStates.Count - 1);
}
}
}
public static LalrItemSet Merge(LalrItemSet a, LalrItemSet b)
{
HashSet <LalrItem> items = new HashSet <LalrItem>();
foreach (var item in a)
{
items.Add(item);
}
foreach (var item in b)
{
items.Add(item);
}
return(new LalrItemSet(items));
}
public bool Equals(LalrItemSet other)
{
if (other == null)
{
return(false);
}
if (this.Count != other.Count)
{
return(false);
}
for (int i = 0; i < other.Count; i++)
{
if (this[i] != other[i])
{
return(false);
}
}
return(true);
}