private string dumpReductionAction(ReductionAction <int, object> reductionAction, string symbolTypeName, Func <int, string> symbolNameConvert, string treeNodeName)
{
string accept_horizon = dumpSymbolChunkSet(reductionAction.AcceptHorizon, symbolTypeName, symbolNameConvert);
string reject_horizon = dumpSymbolChunkSet(reductionAction.RejectHorizon, symbolTypeName, symbolNameConvert);
return("ReductionAction.Create(" + dumpNfaCell(reductionAction.Cell, symbolTypeName, symbolNameConvert, treeNodeName)
+ (accept_horizon != null || reject_horizon != null ? ",/*accept*/" + (accept_horizon != null ? accept_horizon : CodeWords.Null) + ",/*reject*/" + (reject_horizon != null ? reject_horizon : CodeWords.Null) : "")
+ ")");
}
internal static ReductionAction <SYMBOL_ENUM, TREE_NODE> Create <SYMBOL_ENUM, TREE_NODE>(SingleState <SYMBOL_ENUM, TREE_NODE> state,
CoverSets <SYMBOL_ENUM> coverSets,
HorizonSets <SYMBOL_ENUM> horizonSets)
where SYMBOL_ENUM : struct
where TREE_NODE : class
{
SymbolChunkSet <SYMBOL_ENUM> cover = coverSets[state.LhsSymbol];
SymbolChunkSet <SYMBOL_ENUM> horizon = horizonSets[state.LhsSymbol];
// if we have internal conflict between symbols, we cannot use horizon data (because we couldn't tell if we reached horizon)
bool use_horizon = !horizon.IsEmpty && !cover.Overlaps(horizon);
var action = new ReductionAction <SYMBOL_ENUM, TREE_NODE>(state.CreateCell(), use_horizon ? horizon : null,
use_horizon ? new SymbolChunkSet <SYMBOL_ENUM>() : null);
return(action);
}
private bool disambiguateShiftReduceConflictOnHorizon(SingleState <SYMBOL_ENUM, TREE_NODE> shiftItem,
ReductionAction <SYMBOL_ENUM, TREE_NODE> reduceAction)
{
foreach (SYMBOL_ENUM incoming in shiftItem.RhsUnseenSymbols)
{
if (!coverSets[incoming].Overlaps(coverSets[reduceAction.Cell.LhsSymbol]) &&
!coverSets[incoming].Overlaps(reduceAction.AcceptHorizon))
{
// we have to use cover set, and not the incoming symbol, because
// it could be non-terminal, and those do NOT exist by definition in the input stream, only on stack
reduceAction.RejectHorizon.Add(coverSets[incoming]);
return(true);
}
}
if (!shiftItem.AfterLookaheads.Overlaps(coverSets[reduceAction.Cell.LhsSymbol]) &&
!shiftItem.AfterLookaheads.Overlaps(reduceAction.AcceptHorizon))
{
reduceAction.RejectHorizon.Add(shiftItem.AfterLookaheads);
return(true);
}
return(false);
}
public void AddReduce(int sourceNodeId, SymbolChunk <SYMBOL_ENUM> inputChunk, SingleState <SYMBOL_ENUM, TREE_NODE> reductionItem)
{
setSingle(sourceNodeId, inputChunk, new ParseAction <SYMBOL_ENUM, TREE_NODE>(false, ReductionAction.Create(reductionItem.CreateCell())));
}