internal static SliceProperties Abs(SliceProperties stepIndexer)
{
if (stepIndexer.step < 0)
{
stepIndexer.step = -stepIndexer.step;
stepIndexer.from -= stepIndexer.step * (stepIndexer.count - 1);
}
return(stepIndexer);
}
internal static SliceProperties Abs(SliceProperties stepIndexer)
{
if (stepIndexer.step < 0)
{
stepIndexer.step = -stepIndexer.step;
stepIndexer.from -= stepIndexer.step * (stepIndexer.count - 1);
}
return stepIndexer;
}
internal static SliceProperties Calculate(int?from, int?to, int step, int count)
{
if (step == 0)
{
throw new ArgumentException("Step cannot be zero.");
}
var result = new SliceProperties();
if (count == 0)
{
result.count = 0;
return(result);
}
int fromValue, toValue;
if (step > 0)
{
fromValue = from ?? 0;
toValue = to ?? count;
if (fromValue < 0)
{
fromValue += count;
if (fromValue < 0)
{
fromValue = 0;
}
}
else if (fromValue >= count)
{
return(result);
}
if (toValue < 0)
{
toValue += count;
}
if (toValue <= fromValue)
{
return(result);
}
if (toValue > count)
{
toValue = count;
}
result.count = (toValue - fromValue + step - 1) / step;
}
else
{
fromValue = from ?? count - 1;
if (fromValue < 0)
{
fromValue += count;
if (fromValue < 0)
{
return(result);
}
}
else if (fromValue >= count)
{
fromValue = count - 1;
}
if (to < 0)
{
to += count;
}
toValue = to ?? -1;
if (toValue < -1)
{
toValue = -1;
}
else if (toValue >= fromValue)
{
return(result);
}
var absStep = -step;
result.count = (fromValue - toValue - 1 + absStep) / absStep;
}
result.from = fromValue;
result.step = step;
return(result);
}
internal static SliceProperties Calculate(int? from, int? to, int step, int count)
{
if (step == 0)
throw new ArgumentException("Step cannot be zero.");
var result = new SliceProperties();
if (count == 0)
{
result.count = 0;
return result;
}
int fromValue, toValue;
if (step > 0)
{
fromValue = from ?? 0;
toValue = to ?? count;
if (fromValue < 0)
{
fromValue += count;
if (fromValue < 0)
fromValue = 0;
}
else if (fromValue >= count)
return result;
if (toValue < 0)
toValue += count;
if (toValue <= fromValue)
return result;
if (toValue > count)
toValue = count;
result.count = (toValue - fromValue + step - 1) / step;
}
else
{
fromValue = from ?? count - 1;
if (fromValue < 0)
{
fromValue += count;
if (fromValue < 0)
return result;
}
else if (fromValue >= count)
fromValue = count - 1;
if (to < 0)
to += count;
toValue = to ?? -1;
if (toValue < -1)
toValue = -1;
else if (toValue >= fromValue)
return result;
var absStep = -step;
result.count = (fromValue - toValue - 1 + absStep) / absStep;
}
result.from = fromValue;
result.step = step;
return result;
}
