internal bool ComputeShiftAfterLookaheads(Func <int> timeStamp)
{
if (!AfterLookaheads.Add(shiftParents.Select(it => it.AfterLookaheads.Chunks).Flatten()))
{
return(false);
}
lookaheadsStamp = timeStamp();
return(true);
}
internal bool ComputeClosureAfterLookaheads(Func <int> timeStamp,
Dictionary <Production <SYMBOL_ENUM, TREE_NODE>, Dictionary <int, SymbolChunkSet <SYMBOL_ENUM> > > precomputedRhsFirsts,
int lookaheadWidth)
{
int capacity = 0;
foreach (SingleState <SYMBOL_ENUM, TREE_NODE> source in closureParents)
{
// equals -- deals with recursive closure so comparing stamp of the same state
// and since we use "=" in comparison now we can initialize states stamps with the same value
if (source.lookaheadsStamp >= this.lookaheadsStamp)
{
// not the exact science, rather educated guess, plus little something extra
// this calculation is rather OK with lookaheadWidth=1, but with >1 is more and more off
capacity += Math.Max(source.AfterLookaheads.Count,
precomputedRhsFirsts[source.Production][source.RhsSeenCount + 1].Count) + 1;
}
}
if (capacity == 0)
{
return(false);
}
var buffer = new List <SymbolChunk <SYMBOL_ENUM> >(capacity);
foreach (SingleState <SYMBOL_ENUM, TREE_NODE> source in closureParents)
{
if (source.lookaheadsStamp >= this.lookaheadsStamp)
{
bufferCombinedLookaheads(precomputedRhsFirsts,
source.Production,
source.RhsSeenCount + 1,
source.AfterLookaheads,
lookaheadWidth,
buffer);
}
}
if (AfterLookaheads.Add(buffer))
{
lookaheadsStamp = timeStamp();
return(true);
}
else
{
return(false);
}
}
public bool Merge(SingleState <SYMBOL_ENUM, TREE_NODE> incoming, Func <int> timeStamp)
{
// here do not merge closure, because closures are inter-node links
// and the incoming state will be deleted -- thus all inter-node links
// would be invalid (in sense of grammar)
shiftParents.AddRange(incoming.shiftParents);
if (!AfterLookaheads.Add(incoming.AfterLookaheads))
{
return(false);
}
lookaheadsStamp = timeStamp();
return(true);
}
public string ToString(StringRep <SYMBOL_ENUM> symbolsRep)
{
// lowering the case so we can search a string more effectively in DFA text file
string next_lookaheads = NextLookaheads.ToString(symbolsRep, verboseMode: false).ToLower();
string after_lookaheads = AfterLookaheads.ToString(symbolsRep, verboseMode: false).ToLower();
var source = new List <string>();
if (closureParents.Any())
{
source.AddRange(closureParents.Select(it => "c:" + it.IndexStr));
}
if (shiftParents.Any())
{
source.AddRange(shiftParents.Select(it => "s:" + it.IndexStr));
}
return(IndexStr + ") " + symbolsRep.Get(LhsSymbol) + " := "
+ (String.Join(" ", Production.RhsSymbols.Take(RhsSeenCount).Select(it => symbolsRep.Get(it)))
+ " . "
+ String.Join(" ", Production.RhsSymbols.Skip(RhsSeenCount).Select(it => symbolsRep.Get(it)))).Trim()
+ (next_lookaheads.Length > 0 ? "\t (n: " + next_lookaheads + " )" : "")
+ (after_lookaheads.Length > 0 ? "\t (a: " + after_lookaheads + " )" : "")
+ (source.Any() ? "\t <-- " + source.Join(" ") : ""));
}
