private void ProcessQ(int i)
{
if (i < _a.Count)
{
// create an SPPF node v labelled(a_i, i, i + 1)
var v2 = new SppfWord(_a[i], i, i + 1);
// while Q ̸= ∅ {
while (!_Q.IsEmpty)
{
// remove an element, Λ = (B ::= α · a_i β, h, w) say, from Q
var Λ = _Q.TakeOne();
if (Λ.DecoratedProduction.NextWord != _a[i])
{
throw new Exception();
// continue;
}
var h = Λ.StartPosition;
var w = Λ.SppfNode;
var β0 = Λ.DecoratedProduction.TailFirst;
// let y = MAKE NODE(B ::= α a_i · β, h, i + 1, w, v, V)
var productionAdvanced = Λ.DecoratedProduction.Increment();
var y = MakeNode(productionAdvanced, h, i + 1, w, v2);
var newItem = new EarleyItem(productionAdvanced, h, y);
// if β ∈ Σ_N { add (B ::= α a_i · β, h, y) to E_i+1 }
if (PrefixInSigma(β0))
{
_E[i + 1].Add(newItem);
}
// if β = a_i+1 β′ { add (B ::= α a_i · β, h, y) to Q′ }
else
{
if (i + 1 < _a.Count)
{
var aNext = _a[i + 1];
if (β0 == aNext)
{
_QPrime.Add(newItem);
}
}
}
}
}
}
private void ProcessR(int i, Dictionary <Nonterminal, SppfNode> H, EarleySet R)
{
// while R ̸= ∅ {
while (!R.IsEmpty)
{
// remove an element, Λ say, from R
var Λ = R.TakeOne();
var nextWord = Λ.DecoratedProduction.NextWord;
// if Λ = (B ::= α · Cβ, h, w) {
if (nextWord is Nonterminal C)
{
Predict(i, H, R, Λ, C);
}
// if Λ = (D ::= α·, h, w) {
else if (nextWord == null)
{
Complete(i, H, R, Λ);
}
else
{
throw new Exception("Didn't expect a terminal");
}
}
}