37 lines
1.1 KiB
C#
37 lines
1.1 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Linq;
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namespace FruityFoundation.Base.Structures;
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public static class MaybeExtensions
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{
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public static Maybe<T> FirstOrEmpty<T>(this IEnumerable<T> collection)
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{
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using var enumerator = collection.GetEnumerator();
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return !enumerator.MoveNext() ? Maybe.Empty<T>() : enumerator.Current;
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}
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public static Maybe<T> FirstOrEmpty<T>(this IEnumerable<T> collection, Func<T, bool> pred)
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{
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foreach (var item in collection)
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if (pred(item))
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return item;
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return Maybe.Empty<T>();
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}
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public static Maybe<TValue> TryGet<TKey, TValue>(this IReadOnlyDictionary<TKey, TValue> dict, TKey key) =>
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dict.TryGetValue(key, out var value) ? Maybe.Just(value) : Maybe.Empty<TValue>();
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public static T? ToNullable<T>(this Maybe<T> item) where T : struct =>
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item.HasValue ? item.Value : null;
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public static IEnumerable<TOutput> Choose<TInput, TOutput>(this IEnumerable<TInput> enumerable, Func<TInput, Maybe<TOutput>> mapper) =>
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enumerable
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.Select(mapper)
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.Where(x => x.HasValue)
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.Select(x => x.Value);
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}
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