ReadOnlyDictionaryView<TKey, TInput, TOutput>
public struct ReadOnlyDictionaryView<TKey, TInput, TOutput> : IReadOnlyDictionary<TKey, TOutput>, IEnumerable<KeyValuePair<TKey, TOutput>>, IEnumerable, IReadOnlyCollection<KeyValuePair<TKey, TOutput>>, IEquatable<ReadOnlyDictionaryView<TKey, TInput, TOutput>>
Represents lazily converted read-only dictionary.
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
namespace DotNext.Collections.Generic
{
[StructLayout(LayoutKind.Auto)]
[System.Runtime.CompilerServices.NullableContext(1)]
[System.Runtime.CompilerServices.Nullable(0)]
public readonly struct ReadOnlyDictionaryView<[System.Runtime.CompilerServices.Nullable(2)] TKey, [System.Runtime.CompilerServices.Nullable(2)] TInput, [System.Runtime.CompilerServices.Nullable(2)] TOutput> : IReadOnlyDictionary<TKey, TOutput>, IEnumerable<KeyValuePair<TKey, TOutput>>, IEnumerable, IReadOnlyCollection<KeyValuePair<TKey, TOutput>>, IEquatable<ReadOnlyDictionaryView<TKey, TInput, TOutput>>
{
[System.Runtime.CompilerServices.Nullable(new byte[] {
2,
1,
1
})]
private readonly IReadOnlyDictionary<TKey, TInput> source;
private readonly Func<TInput, TOutput> mapper;
public TOutput this[TKey key] {
get {
if (source == null)
throw new KeyNotFoundException();
return mapper(source[key]);
}
}
public IEnumerable<TKey> Keys {
get {
IReadOnlyDictionary<TKey, TInput> readOnlyDictionary = source;
return ((readOnlyDictionary != null) ? readOnlyDictionary.Keys : null) ?? Enumerable.Empty<TKey>();
}
}
public IEnumerable<TOutput> Values {
get {
if (source != null && mapper != null)
return Enumerable.Select<TInput, TOutput>(source.Values, mapper);
return Enumerable.Empty<TOutput>();
}
}
public int Count {
get {
IReadOnlyDictionary<TKey, TInput> readOnlyDictionary = source;
if (readOnlyDictionary == null)
return 0;
return readOnlyDictionary.Count;
}
}
public ReadOnlyDictionaryView(IReadOnlyDictionary<TKey, TInput> dictionary, Func<TInput, TOutput> mapper)
{
if (dictionary == null)
throw new ArgumentNullException("dictionary");
source = dictionary;
if (mapper == null)
throw new ArgumentNullException("mapper");
this.mapper = mapper;
}
public ReadOnlyDictionaryView(IReadOnlyDictionary<TKey, TInput> dictionary, Converter<TInput, TOutput> mapper)
{
this = new ReadOnlyDictionaryView<TKey, TInput, TOutput>(dictionary, Unsafe.As<Func<TInput, TOutput>>((object)mapper));
}
public bool ContainsKey(TKey key)
{
return source?.ContainsKey(key) ?? false;
}
[return: System.Runtime.CompilerServices.Nullable(new byte[] {
1,
0,
1,
1
})]
public IEnumerator<KeyValuePair<TKey, TOutput>> GetEnumerator()
{
if (this.source != null) {
foreach (KeyValuePair<TKey, TInput> item in (IEnumerable<KeyValuePair<TKey, TInput>>)this.source) {
item.Deconstruct(out TKey key, out TInput value);
TKey key2 = key;
TInput arg = value;
yield return new KeyValuePair<TKey, TOutput>(key2, this.mapper(arg));
}
}
}
public bool TryGetValue(TKey key, [MaybeNullWhen(false)] out TOutput value)
{
if (source != null && source.TryGetValue(key, out TInput value2)) {
value = mapper(value2);
return true;
}
value = default(TOutput);
return false;
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
private bool Equals([In] [IsReadOnly] [System.Runtime.CompilerServices.Nullable(new byte[] {
0,
1,
1,
1
})] ref ReadOnlyDictionaryView<TKey, TInput, TOutput> other)
{
if (source == other.source)
return mapper == other.mapper;
return false;
}
public bool Equals([System.Runtime.CompilerServices.Nullable(new byte[] {
0,
1,
1,
1
})] ReadOnlyDictionaryView<TKey, TInput, TOutput> other)
{
return Equals(ref other);
}
public override int GetHashCode()
{
return RuntimeHelpers.GetHashCode(source) ^ mapper.GetHashCode();
}
[System.Runtime.CompilerServices.NullableContext(2)]
public override bool Equals(object other)
{
if (!(other is ReadOnlyDictionaryView<TKey, TInput, TOutput>))
return object.Equals(source, other);
ReadOnlyDictionaryView<TKey, TInput, TOutput> other2 = (ReadOnlyDictionaryView<TKey, TInput, TOutput>)other;
return Equals(ref other2);
}
public static bool operator ==([In] [IsReadOnly] [System.Runtime.CompilerServices.Nullable(new byte[] {
0,
1,
1,
1
})] ref ReadOnlyDictionaryView<TKey, TInput, TOutput> first, [In] [IsReadOnly] [System.Runtime.CompilerServices.Nullable(new byte[] {
0,
1,
1,
1
})] ref ReadOnlyDictionaryView<TKey, TInput, TOutput> second)
{
return first.Equals(ref second);
}
public static bool operator !=([In] [IsReadOnly] [System.Runtime.CompilerServices.Nullable(new byte[] {
0,
1,
1,
1
})] ref ReadOnlyDictionaryView<TKey, TInput, TOutput> first, [In] [IsReadOnly] [System.Runtime.CompilerServices.Nullable(new byte[] {
0,
1,
1,
1
})] ref ReadOnlyDictionaryView<TKey, TInput, TOutput> second)
{
return !first.Equals(ref second);
}
}
}