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andryushchenkoandryushchenko
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[ADD] Enumerable.LastOrNone
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3 files changed

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‎src/AInq.Optional.Async/MaybeAsync.Linq.Enumerator.cs‎

Lines changed: 63 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -98,6 +98,45 @@ public async ValueTask<Maybe<T>> FirstOrNoneAsync([InstantHandle(RequireAwait =
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return enumerator.Current;
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return Maybe.None<T>();
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}
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/// <inheritdoc cref="Maybe.LastOrNone{T}(IEnumerable{T})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastOrNoneAsync(CancellationToken cancellation = default)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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var result = Maybe.None<T>();
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await foreach (var value in collection.WithCancellation(cancellation).ConfigureAwait(false))
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result = value;
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return result;
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}
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/// <inheritdoc cref="Maybe.LastOrNone{T}(IEnumerable{T},Func{T,bool})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastOrNoneAsync([InstantHandle(RequireAwait = true)] Func<T, bool> filter,
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CancellationToken cancellation = default)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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_ = filter ?? throw new ArgumentNullException(nameof(filter));
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var result = Maybe.None<T>();
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await foreach(var value in collection.WithCancellation(cancellation).ConfigureAwait(false))
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if (filter.Invoke(value))
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result = value;
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return result;
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}
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/// <inheritdoc cref="Maybe.LastOrNone{T}(IEnumerable{T},Func{T,bool})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastOrNoneAsync([InstantHandle(RequireAwait = true)] Func<T, CancellationToken, ValueTask<bool>> filter,
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CancellationToken cancellation = default)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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_ = filter ?? throw new ArgumentNullException(nameof(filter));
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var result = Maybe.None<T>();
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await foreach(var value in collection.WithCancellation(cancellation).ConfigureAwait(false))
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if (await filter.Invoke(value, cancellation).ConfigureAwait(false))
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result = value;
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return result;
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}
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/// <inheritdoc cref="Maybe.SingleOrNone{T}(IEnumerable{T})" />
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[PublicAPI]
@@ -169,6 +208,18 @@ public async ValueTask<Maybe<T>> FirstNotNullOrNoneAsync(CancellationToken cance
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return enumerator.Current;
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return Maybe.None<T>();
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}
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/// <inheritdoc cref="Maybe.LastNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastNotNullOrNoneAsync(CancellationToken cancellation = default)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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var result = Maybe.None<T>();
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await foreach(var value in collection.WithCancellation(cancellation).ConfigureAwait(false))
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if (value is not null)
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result = value;
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return result;
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}
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/// <inheritdoc cref="Maybe.SingleNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]
@@ -205,6 +256,18 @@ public async ValueTask<Maybe<T>> FirstNotNullOrNoneAsync(CancellationToken cance
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return enumerator.Current.Value;
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return Maybe.None<T>();
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}
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/// <inheritdoc cref="Maybe.LastNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastNotNullOrNoneAsync(CancellationToken cancellation = default)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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var result = Maybe.None<T>();
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await foreach(var value in collection.WithCancellation(cancellation).ConfigureAwait(false))
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if (value.HasValue)
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result = value;
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return result;
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}
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/// <inheritdoc cref="Maybe.SingleNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]

‎src/AInq.Optional.Async/MaybeAsync.Linq.Query.cs‎

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Original file line numberDiff line numberDiff line change
@@ -80,6 +80,34 @@ public async ValueTask<Maybe<T>> FirstOrNoneAsync([InstantHandle(RequireAwait =
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_ = filter ?? throw new ArgumentNullException(nameof(filter));
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return await collection.Where(filter).Select(Maybe<T>.FromValue).FirstOrDefaultAsync(Maybe.None<T>(), cancellation).ConfigureAwait(false);
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}
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/// <inheritdoc cref="Maybe.LastOrNone{T}(IEnumerable{T})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastOrNoneAsync(CancellationToken cancellation = default)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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return await collection.Select(Maybe<T>.FromValue).LastOrDefaultAsync(Maybe.None<T>(), cancellation).ConfigureAwait(false);
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}
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/// <inheritdoc cref="Maybe.LastOrNone{T}(IEnumerable{T},Func{T,bool})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastOrNoneAsync([InstantHandle(RequireAwait = true)] Func<T, bool> filter,
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CancellationToken cancellation = default)
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{
97+
_ = collection ?? throw new ArgumentNullException(nameof(collection));
98+
_ = filter ?? throw new ArgumentNullException(nameof(filter));
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return await collection.Where(filter).Select(Maybe<T>.FromValue).LastOrDefaultAsync(Maybe.None<T>(), cancellation).ConfigureAwait(false);
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}
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/// <inheritdoc cref="Maybe.LastOrNone{T}(IEnumerable{T},Func{T,bool})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastOrNoneAsync([InstantHandle(RequireAwait = true)] Func<T, CancellationToken, ValueTask<bool>> filter,
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CancellationToken cancellation = default)
106+
{
107+
_ = collection ?? throw new ArgumentNullException(nameof(collection));
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_ = filter ?? throw new ArgumentNullException(nameof(filter));
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return await collection.Where(filter).Select(Maybe<T>.FromValue).LastOrDefaultAsync(Maybe.None<T>(), cancellation).ConfigureAwait(false);
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}
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84112
/// <inheritdoc cref="Maybe.SingleOrNone{T}(IEnumerable{T})" />
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[PublicAPI]
@@ -130,6 +158,16 @@ public async ValueTask<Maybe<T>> FirstNotNullOrNoneAsync(CancellationToken cance
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.FirstOrDefaultAsync(maybe => maybe.HasValue, Maybe<T>.None, cancellation)
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.ConfigureAwait(false);
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}
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/// <inheritdoc cref="Maybe.LastNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastNotNullOrNoneAsync(CancellationToken cancellation = default)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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return await collection.Select(Maybe.ValueIfNotNull)
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.LastOrDefaultAsync(maybe => maybe.HasValue, Maybe<T>.None, cancellation)
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.ConfigureAwait(false);
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}
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134172
/// <inheritdoc cref="Maybe.SingleNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]
@@ -156,6 +194,16 @@ public async ValueTask<Maybe<T>> FirstNotNullOrNoneAsync(CancellationToken cance
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.FirstOrDefaultAsync(maybe => maybe.HasValue, Maybe<T>.None, cancellation)
157195
.ConfigureAwait(false);
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}
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/// <inheritdoc cref="Maybe.LastNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]
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public async ValueTask<Maybe<T>> LastNotNullOrNoneAsync(CancellationToken cancellation = default)
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{
202+
_ = collection ?? throw new ArgumentNullException(nameof(collection));
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return await collection.Select(Maybe.ValueIfNotNull)
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.LastOrDefaultAsync(maybe => maybe.HasValue, Maybe<T>.None, cancellation)
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.ConfigureAwait(false);
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}
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160208
/// <inheritdoc cref="Maybe.SingleNotNullOrNone{T}(IEnumerable{T?})" />
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[PublicAPI]

‎src/AInq.Optional/Maybe.Linq.cs‎

Lines changed: 54 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -94,6 +94,34 @@ public Maybe<T> FirstOrNone([InstantHandle] Func<T, bool> filter)
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return collection.Where(filter).Select(Maybe<T>.FromValue).FirstOrDefault(Maybe<T>.None);
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#endif
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}
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/// <summary> Get last value or none </summary>
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/// <returns> Maybe </returns>
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[PublicAPI]
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public Maybe<T> LastOrNone()
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{
103+
_ = collection ?? throw new ArgumentNullException(nameof(collection));
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#if NETSTANDARD
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return collection.Select(Maybe<T>.FromValue).LastOrDefault() ?? Maybe<T>.None;
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#else
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return collection.Select(Maybe<T>.FromValue).LastOrDefault(Maybe<T>.None);
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#endif
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}
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/// <summary> Get last matching value or none </summary>
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/// <param name="filter"> Filter </param>
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/// <returns> Maybe </returns>
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[PublicAPI]
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public Maybe<T> LastOrNone([InstantHandle] Func<T, bool> filter)
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{
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_ = collection ?? throw new ArgumentNullException(nameof(collection));
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_ = filter ?? throw new ArgumentNullException(nameof(filter));
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#if NETSTANDARD
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return collection.Where(filter).Select(Maybe<T>.FromValue).LastOrDefault() ?? Maybe<T>.None;
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#else
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return collection.Where(filter).Select(Maybe<T>.FromValue).LastOrDefault(Maybe<T>.None);
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#endif
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}
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98126
/// <summary> Get single value or none </summary>
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/// <returns> Maybe </returns>
@@ -143,6 +171,19 @@ public Maybe<T> FirstNotNullOrNone()
143171
return collection.Select(ValueIfNotNull).FirstOrDefault(maybe => maybe.HasValue, Maybe<T>.None);
144172
#endif
145173
}
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/// <summary> Get last not null value or none </summary>
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/// <returns> Maybe </returns>
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[PublicAPI]
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public Maybe<T> LastNotNullOrNone()
179+
{
180+
_ = collection ?? throw new ArgumentNullException(nameof(collection));
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#if NETSTANDARD
182+
return collection.Select(ValueIfNotNull).LastOrDefault(maybe => maybe.HasValue) ?? Maybe<T>.None;
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#else
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return collection.Select(ValueIfNotNull).LastOrDefault(maybe => maybe.HasValue, Maybe<T>.None);
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#endif
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}
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147188
/// <summary> Get single not null value or none </summary>
148189
/// <returns> Maybe </returns>
@@ -175,6 +216,19 @@ public Maybe<T> FirstNotNullOrNone()
175216
return collection.Select(ValueIfNotNull).FirstOrDefault(maybe => maybe.HasValue, Maybe<T>.None);
176217
#endif
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}
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/// <summary> Get last not null value or none </summary>
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/// <returns> Maybe </returns>
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[PublicAPI]
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public Maybe<T> LastNotNullOrNone()
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{
225+
_ = collection ?? throw new ArgumentNullException(nameof(collection));
226+
#if NETSTANDARD
227+
return collection.Select(ValueIfNotNull).LastOrDefault(maybe => maybe.HasValue) ?? Maybe<T>.None;
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#else
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return collection.Select(ValueIfNotNull).LastOrDefault(maybe => maybe.HasValue, Maybe<T>.None);
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#endif
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}
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/// <inheritdoc cref="SingleNotNullOrNone{T}(IEnumerable{T})" />
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[PublicAPI]

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