/// <summary>
/// Honalee algorithm
/// </summary>
/// <param name="state"></param>
/// <param name="actionBuilder"></param>
/// <param name="queue"></param>
private void Goto(State state, ActionBuilder actionBuilder, Queue <State> queue)
{
foreach (var symbol in state.NextSymbols())
{
var newState = new State(States.Count, symbol);
foreach (var item in state.Where(x => x.IsSymbol(symbol)))
{
newState.Add(item.Production, item.Position + 1, item.Lookahead);
}
if (newState.Count > 0)
{
if (!States.TryGetId(newState, out var stateId))
{
States.Add(newState);
newState.Closure(grammar);
queue.Enqueue(newState);
stateId = newState.Index;
}
actionBuilder.AddGoto(state.Index, symbol.Id, stateId);
//For debug purposes, we'll record the transition it the item
foreach (var item in state.Where(x => x.IsSymbol(symbol)))
{
item.SetGoto(stateId);
}
}
}
foreach (var item in state.Where(x => x.AtEnd))
{
actionBuilder.AddReduce(state.Index, item.Lookahead.Id, item.Production.Id);
}
}
public LR1Parser(ILogger logger,
Grammar grammar,
ConflictList conflicts)
{
this.grammar = grammar;
var endSymbol = grammar.Symbols[0];
//Honalee Algorithm
//Create kernel item from augmented gramar production
var kernel = new LR1Item(grammar[0], 0, endSymbol);
var startState = new State(0)
{
kernel
};
States = new States {
startState
};
startState.Closure(this.grammar);
var queue = new Queue <State>();
queue.Enqueue(startState);
var actionBuilder = new ActionBuilder(this.grammar);
//Method2
while (queue.Count > 0)
{
startState = queue.Dequeue();
Goto(startState, actionBuilder, queue);
}
var resolver = new ConflictResolvers(conflicts,
grammar.Symbols,
logger);
Actions = actionBuilder.Build(logger,
States,
this.grammar.Symbols,
resolver);
}
