public static IndexedItem <TSource> MinIndexedItem <TSource>(this IEnumerable <TSource> source, Func <TSource, int> selector)
{
ArgumentNullException.ThrowIfNull(source);
ArgumentNullException.ThrowIfNull(selector);
var minIndex = -1;
var minItem = default(TSource);
var minValue = default(int);
var itemIndex = 0;
foreach (var item in source)
{
var value = selector(item);
if (itemIndex == 0 || value < minValue)
{
minIndex = itemIndex;
minItem = item;
minValue = value;
}
++itemIndex;
}
return(IndexedItemFactory.Create(minIndex, minItem));
}
public static IndexedItem <TSource> FirstIndexedItem <TSource>(this IEnumerable <TSource> source, Func <TSource, bool> predicate)
{
ArgumentNullException.ThrowIfNull(source);
ArgumentNullException.ThrowIfNull(predicate);
var firstIndex = -1;
var firstItem = default(TSource);
foreach (var item in source)
{
++firstIndex;
if (predicate(item))
{
firstItem = item;
break;
}
}
return(IndexedItemFactory.Create(firstIndex, firstItem));
}
public static IndexedItem <TSource> ExtremumIndexedItem <TSource>(this IEnumerable <TSource> source, Func <TSource, TSource, bool> firstArgumentIsExtremum)
{
ArgumentNullException.ThrowIfNull(source);
ArgumentNullException.ThrowIfNull(firstArgumentIsExtremum);
var extremumIndex = -1;
var extremumItem = default(TSource);
var itemIndex = 0;
foreach (var item in source)
{
if (itemIndex == 0 || firstArgumentIsExtremum(item, extremumItem))
{
extremumIndex = itemIndex;
extremumItem = item;
}
++itemIndex;
}
return(IndexedItemFactory.Create(extremumIndex, extremumItem));
}
public static IEnumerable <IndexedItem <T> > SelectIndexed <T>(this IEnumerable <T> source) => source.Select((item, i) => IndexedItemFactory.Create(i, item));
