Pillole video 17

fcamuso

Jun 14th, 2025

284

Never

Add comment

Not a member of Pastebin yet? Sign Up, it unlocks many cool features!

C# 1.90 KB | None | 0 0

raw download clone embed print report

public static class EnumerableExtensions
{
// da usare con 'foreeach' per ottenrere l'indice
public static IEnumerable<(T, int)> WithIndex<T>(this IEnumerable<T> items,
int skip = 0, bool useSkipped = true)
{
if (skip < 0) throw new ArgumentOutOfRangeException(nameof(skip), "value not valid");
return items.Select((value, index) => (value, useSkipped ? index : index - skip)).Skip(skip);
}
// foreach direttamente sull'enumeratore (es: items.ForEach(...))
public static void ForEachWithIndex<T>(this IEnumerable<T> items,
Action<T, int> action, int skip = 0, bool useSkipped = false)
{
foreach (var (value, index) in items.WithIndex(skip, useSkipped)) action.Invoke(value, index);
}
// applica where solo se si soddisfa la condizione
public static IEnumerable<T> WhereIf<T>(this IEnumerable<T> items, Func<T, bool> predicate, bool condition = true)
{
return condition ? items.Where(predicate) : items;
}
// Ottiene il conteggio oppure 0 se null
public static int CountOrDefault<T>(this IEnumerable<T>? items, Func<T, bool>? predicate = null)
{
return predicate == null ?
items?.Count() ?? 0 :
items?.Count(predicate) ?? 0;
}
// Concatena stringhe
public static string JoinString(this IEnumerable<string> items, string separator)
=> string.Join(separator, items);
// ForEach Async
public static async Task ForEachAsync<T>(this IEnumerable<T> enumerable,
Func<T, Task> action, CancellationToken token = default)
{
foreach (var item in enumerable)
{
token.ThrowIfCancellationRequested();
await action.Invoke(item).ConfigureAwait(false);
}
}
}

Add Comment

Please, Sign In to add comment