public void Optimize(ISymbol searchSymbol, int index)
{
var earleySet = _chart.EarleySets[index];
var transitiveState = earleySet.FindTransitionState(searchSymbol);
if (transitiveState != null)
{
Transition = transitiveState;
return;
}
var sourceState = earleySet.FindSourceState(searchSymbol);
if (sourceState == null)
return;
var sourceStateNext = sourceState.NextState();
if (!sourceStateNext.IsComplete)
return;
Transition = sourceStateNext;
Optimize(
sourceState.Production.LeftHandSide,
sourceState.Origin);
if (Transition == null)
return;
// TODO:
// 1. create the parse node from the source state
// 2. take the transition item's parse node and add it as the child
// to the source state's parse node
var transitionItem = new TransitionState(
searchSymbol,
Transition,
sourceState,
index);
if (_chart.Enqueue(index, transitionItem))
Log("Transition", index, transitionItem);
}
private void OptimizeReductionPathRecursive(
ISymbol searchSymbol,
int k,
ref IState t_rule,
ref ITransitionState previousTransitionState)
{
var earleySet = _chart.EarleySets[k];
// if Ii contains a transitive item of the for [B -> b., A, k]
var transitionState = earleySet.FindTransitionState(searchSymbol);
if (transitionState != null)
{
// then t_rule := B-> b.; t_pos = k;
previousTransitionState = transitionState;
t_rule = transitionState;
return;
}
// else if Ii contains exactly one item of the form [B -> a.Ab, k]
var sourceState = earleySet.FindSourceState(searchSymbol);
if (sourceState == null)
return;
// and [B-> aA.b, k] is quasi complete (is b null)
if (!IsNextStateQuasiComplete(sourceState))
return;
// then t_rule := [B->aAb.]; t_pos=k;
t_rule = sourceState.NextState();
// T_Update(I0...Ik, B);
OptimizeReductionPathRecursive(
sourceState.Production.LeftHandSide,
sourceState.Origin,
ref t_rule,
ref previousTransitionState);
if (t_rule == null)
return;
ITransitionState currentTransitionState = null;
if (previousTransitionState != null)
{
currentTransitionState = new TransitionState(
searchSymbol,
t_rule,
sourceState,
previousTransitionState.Index);
previousTransitionState.NextTransition = currentTransitionState;
}
else
currentTransitionState = new TransitionState(
searchSymbol,
t_rule,
sourceState,
k);
if (_chart.Enqueue(k, currentTransitionState))
Log("Transition", k, currentTransitionState);
previousTransitionState = currentTransitionState;
}
private void OptimizeReductionPathRecursive(
ISymbol searchSymbol,
int k,
ref IState t_rule,
ref ITransitionState previousTransitionState)
{
var earleySet = _chart.EarleySets[k];
var transitionState = earleySet.FindTransitionState(searchSymbol);
if (transitionState != null)
{
previousTransitionState = transitionState;
t_rule = transitionState;
return;
}
var sourceState = earleySet.FindSourceState(searchSymbol);
if (sourceState == null)
return;
if (!IsNextStateQuasiComplete(sourceState))
return;
t_rule = sourceState.NextState();
OptimizeReductionPathRecursive(
sourceState.Production.LeftHandSide,
sourceState.Origin,
ref t_rule,
ref previousTransitionState);
if (t_rule == null)
return;
ITransitionState currentTransitionState = null;
if (previousTransitionState != null)
{
currentTransitionState = new TransitionState(
searchSymbol,
t_rule,
sourceState,
previousTransitionState.Position);
previousTransitionState.NextTransition = currentTransitionState;
}
else
currentTransitionState = new TransitionState(
searchSymbol,
t_rule,
sourceState,
k);
if (_chart.Enqueue(k, currentTransitionState))
Log("Transition", k, currentTransitionState);
previousTransitionState = currentTransitionState;
}