// MAKE_NODE(B ::= αx · β, j, i, w, v, V) {
private SppfNode MakeNodeSimplified(DecoratedProduction decoratedProduction, int j, int i, SppfNode w, SppfNode v)
{
SppfNode y;
Production production = null;
// if β = ϵ { let s = B } else { let s = (B ::= αx · β) }
if (decoratedProduction.AtEnd)
{
// s = ValueTuple.Create<Word, DecoratedProduction>(decoratedProduction.Production.Lhs, null);
y = _V.GetOrSet(decoratedProduction.Production.Lhs, j, i);
production = decoratedProduction.Production;
}
else
{
// s = ValueTuple.Create<Word, DecoratedProduction>(null, decoratedProduction);
y = _V.GetOrSet(decoratedProduction, j, i);
}
// if w = null and y does not have a family of children (v) add one
if (w == null)
{
y.AddFamily(production, v);
}
// if w ̸= null and y does not have a family of children(w, v) add one
else
{
y.AddFamily(production, w, v);
}
return(y);
}
internal SppfBranch GetOrSet(DecoratedProduction item, int j, int i)
{
var tup = ValueTuple.Create(item, j, i);
SppfBranch y;
if (!_prodDict.TryGetValue(tup, out y))
{
var newY = new SppfBranch(item, j, i);
_prodDict[tup] = newY;
y = newY;
}
return(y);
}
public EarleyItem(DecoratedProduction decoratedProduction, int startPosition, SppfNode sppfNode)
{
if (decoratedProduction == null)
{
throw new ArgumentNullException();
}
DecoratedProduction = decoratedProduction;
StartPosition = startPosition;
SppfNode = sppfNode;
unchecked {
int hash = 17;
hash = hash * 23 + this.DecoratedProduction.GetHashCode();
hash = hash * 23 + this.StartPosition.GetHashCode();
_cachedHash = hash;
}
}
// MAKE_NODE(B ::= αx · β, j, i, w, v, V) {
private SppfNode MakeNodeOriginal(DecoratedProduction decoratedProduction, int j, int i, SppfNode w, SppfNode v)
{
// var α = decoratedProduction.Prefix;
// if α = ϵ and β ̸= ϵ { let y = v }
if (decoratedProduction.CurrentPosition == 1 && !decoratedProduction.AtEnd)
{
return(v);
}
Production production = null;
SppfNode y;
// if β = ϵ { let s = B } else { let s = (B ::= αx · β) }
// if there is no node y ∈ V labelled (s,j,i) create one and add it to V
if (decoratedProduction.AtEnd)
{
production = decoratedProduction.Production;
var s = production.Lhs;
y = _V.GetOrSet(s, j, i);
}
else
{
var s = decoratedProduction;
y = _V.GetOrSet(s, j, i);
}
// if w = null and y does not have a family of children (v) add one
if (w == null)
{
y.AddFamily(production, v);
}
// if w ̸= null and y does not have a family of children(w, v) add one
else
{
y.AddFamily(production, w, v);
}
return(y);
}
// MAKE_NODE(B ::= αx · β, j, i, w, v, V) {
private SppfNode MakeNode(DecoratedProduction decoratedProduction, int j, int i, SppfNode w, SppfNode v)
{
return(MakeNodeOriginal(decoratedProduction, j, i, w, v));
}
