private void LeoReductionOperation(int iLoc, CachedStateFrameTransition fromLim)
{
var fromAH = fromLim.Frame;
var transSym = fromLim.Symbol;
var originLoc = fromLim.Origin;
var toAH = Goto(fromAH, transSym);
if (toAH == null)
{
return;
}
AddEimPair(iLoc, toAH, originLoc);
}
private void MemoizeTransitions(int iLoc)
{
var frameSet = Chart.FrameSets[iLoc];
// leo eligibility needs to be cached before creating the cached transition
// if the size of the list is != 1, do not enter the cached frame transition
var cachedTransitionsPool = SharedPools.Default <Dictionary <ISymbol, CachedStateFrameTransition> >();
var cachedTransitions = cachedTransitionsPool.AllocateAndClear();
var cachedCountPool = SharedPools.Default <Dictionary <ISymbol, int> >();
var cachedCount = cachedCountPool.AllocateAndClear();
for (var i = 0; i < frameSet.Frames.Count; i++)
{
var stateFrame = frameSet.Frames[i];
for (var j = 0; j < stateFrame.Frame.Data.Count; j++)
{
var preComputedState = stateFrame.Frame.Data[j];
if (IsCompleted(preComputedState))
{
continue;
}
var postDotSymbol = GetPostDotSymbol(preComputedState);
if (postDotSymbol.SymbolType != SymbolType.NonTerminal)
{
continue;
}
// leo eligibile items are right recursive directly or indirectly
if (!_preComputedGrammar.IsRightRecursive(
preComputedState.Production.LeftHandSide))
{
continue;
}
// to determine if the item is leo unique, cache it here
var count = 0;
if (!cachedCount.TryGetValue(postDotSymbol, out count))
{
cachedCount[postDotSymbol] = 1;
var origin = stateFrame.Origin;
CachedStateFrameTransition topCacheItem = null;
while (true)
{
var originFrameSet = Chart.FrameSets[stateFrame.Origin];
var nextCachedItem = originFrameSet.FindCachedStateFrameTransition(postDotSymbol);
if (nextCachedItem == null)
{
break;
}
topCacheItem = nextCachedItem;
if (origin == nextCachedItem.Origin)
{
break;
}
origin = topCacheItem.Origin;
}
cachedTransitions[postDotSymbol] = new CachedStateFrameTransition(
postDotSymbol,
stateFrame.Frame,
topCacheItem == null ? stateFrame.Origin : origin);
}
else
{
cachedCount[postDotSymbol] = count + 1;
}
}
}
// add all memoized leo items to the frameSet
foreach (var symbol in cachedCount.Keys)
{
var count = cachedCount[symbol];
if (count != 1)
{
continue;
}
frameSet.AddCachedTransition(cachedTransitions[symbol]);
}
cachedTransitionsPool.ClearAndFree(cachedTransitions);
cachedCountPool.ClearAndFree(cachedCount);
}
