private bool TryHandleSkipLevels(out double score)
{
if (this.skipLevelsHandled)
{
score = 0;
return(false);
}
else
{
if (this.skipLevels <= 0)
{
return(this.HandleSkipLevelsFailed(out score));
}
else if (this.skipLevels == 1)
{
MCTS <T> chosenChild;
if (!TryChooseChildForExecute(out chosenChild) ||
0 < chosenChild._visits
)
{
return(this.HandleSkipLevelsFailed(out score));
}
else
if (chosenChild.Execute(out score))
{
return(true);
}
else
{
throw new InvalidOperationException();
}
}
else
{
while (true)
{
MCTS <T> chosenChild;
if (!TryChooseChildForTryHandleSkipLevels(out chosenChild))
{
return(this.HandleSkipLevelsFailed(out score));
}
else if (chosenChild.TryHandleSkipLevels(out score))
{
return(true);
}
else if (!chosenChild.skipLevelsHandled)
{
throw new InvalidOperationException(
"Child didn't handle skip levels."
);
}
}
}
}
}
private bool HandleSkipLevelsFailed(out double score)
{
this.skipLevelsHandled = true;
score = 0;
return(false);
}
private bool Execute(out double score)
{
score = 0;
bool result = false;
if (this._complete)
{
return(false);
}
else if (!this.skipLevelsHandled)
{
Interlocked.Increment(ref this._visits);
if (this.TryHandleSkipLevels(out score))
{
if (score < 0)
{
throw new ArgumentOutOfRangeException(
"IMCTSGame.Score must not be negative."
);
}
result = true;
}
else
{
Interlocked.Decrement(ref this._visits);
}
}
if (!result)
{
if (Interlocked.CompareExchange(ref this._visits, 1, 0) == 0)
{
result = true;
score = this.Node.Value;
if (score < 0)
{
throw new ArgumentOutOfRangeException(
"IMCTSGame.Score must not be negative."
);
}
}
else
{
Interlocked.Increment(ref this._visits);
while (!result)
{
MCTS <T> chosenChild;
if (!TryChooseChildForExecute(out chosenChild))
{
break;
}
result = chosenChild.Execute(out score);
if (!result && !chosenChild.Complete)
{
throw new InvalidOperationException(
"Node didn't execute and Complete is false."
);
}
}
}
}
if (result)
{
this.score.Add(score);
}
else
{
Interlocked.Decrement(ref this._visits);
this._complete = true;
}
return(result);
}
