/// <summary>
/// Flattens this <see cref="IPagedEnumerable{T}"/> into an <see cref="IAsyncEnumerable{T}"/>.
/// </summary>
/// <returns>
/// A flattened <see cref="IAsyncEnumerable{T}"/> of <typeparamref name="TEntity"/>s.
/// </returns>
public static async IAsyncEnumerable <TEntity> Flatten <TEntity>(this IPagedEnumerable <TEntity> source, [EnumeratorCancellation] CancellationToken cancellationToken = default)
where TEntity : class
{
Guard.IsNotNull(source);
await foreach (var page in source.WithCancellation(cancellationToken).ConfigureAwait(false))
{
foreach (var entity in page)
{
yield return(entity);
}
}
}
/// <summary>
/// Flattens this <see cref="IPagedEnumerable{T}"/> into a single list.
/// </summary>
/// <returns>
/// A flattened list of <typeparamref name="TEntity"/>s.
/// </returns>
public static async Task <IReadOnlyList <TEntity> > FlattenAsync <TEntity>(this IPagedEnumerable <TEntity> source, CancellationToken cancellationToken = default)
where TEntity : class
{
Guard.IsNotNull(source);
var list = new List <TEntity>();
await foreach (var page in source.WithCancellation(cancellationToken).ConfigureAwait(false))
{
list.AddRange(page);
}
return(list);
}
public static async Task <IReadOnlyList <TEntity> > FirstOrDefaultPageAsync <TEntity>(this IPagedEnumerable <TEntity> source, Predicate <IReadOnlyList <TEntity> > predicate, CancellationToken cancellationToken = default)
where TEntity : class
{
Guard.IsNotNull(source);
Guard.IsNotNull(predicate);
await foreach (var page in source.WithCancellation(cancellationToken).ConfigureAwait(false))
{
if (predicate(page))
{
return(page);
}
}
return(null);
}
public static async Task <TEntity> FirstOrDefaultAsync <TEntity>(this IPagedEnumerable <TEntity> source, Predicate <TEntity> predicate, CancellationToken cancellationToken = default)
where TEntity : class
{
Guard.IsNotNull(source);
Guard.IsNotNull(predicate);
await foreach (var page in source.WithCancellation(cancellationToken).ConfigureAwait(false))
{
for (var i = 0; i < page.Count; i++)
{
var entity = page[i];
if (predicate(entity))
{
return(entity);
}
}
}
return(null);
}
