public IEnumerable <TEdit> CalculateEdit <TEdit>(
ILevenstainMatrix matrix,
IList <TSource> source,
IList <TTarget> target,
Func <TSource, TTarget, TEdit> editSelector,
bool reverse = false)
{
var result = InternalCalculateEdit(matrix, source, target, editSelector);
return(reverse ? result : result.Reverse()); //default is already reversed
}
private IEnumerable <TEdit> InternalCalculateEdit <TEdit>(
ILevenstainMatrix matrix,
IList <TSource> source,
IList <TTarget> target,
Func <TSource, TTarget, TEdit> editSelector)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (target == null)
{
throw new ArgumentNullException(nameof(target));
}
if (editSelector == null)
{
throw new ArgumentNullException(nameof(editSelector));
}
if (matrix == null)
{
throw new ArgumentNullException(nameof(matrix));
}
if (matrix.M != (source.Count + 1) || matrix.N != (target.Count + 1))
{
throw new ArgumentOutOfRangeException("Invalid matrix size.");
}
if (Options == null)
{
throw new ArgumentNullException(nameof(Options));
}
int i = matrix.M - 1;
int j = matrix.N - 1;
while (i != 0 || j != 0)
{
if (i == 0)
{
yield return(editSelector(default(TSource), target[j - 1]));
j--;
continue;
}
if (j == 0)
{
yield return(editSelector(source[i - 1], default(TTarget)));
i--;
continue;
}
var ss1 = source[i - 1];
var ss2 = target[j - 1];
var diag = matrix[i - 1, j - 1] + Options.GetUpdateCost(ss1, ss2);
var left = matrix[i, j - 1] + Options.GetCreateCost(ss2);
var up = matrix[i - 1, j] + Options.GetDeleteCost(ss1);
if (diag <= left && diag <= up)
{
yield return(editSelector(ss1, ss2));
i--;
j--;
}
else if (left <= diag && left <= up)
{
yield return(editSelector(default(TSource), ss2));
j--;
}
else if (up <= diag && up <= left)
{
yield return(editSelector(ss1, default(TTarget)));
i--;
}
else
{
throw new InvalidOperationException();
}
}
}
