| | | 1 | | using System.Collections.ObjectModel; |
| | | 2 | | |
| | | 3 | | namespace MoreStructures.Utilities; |
| | | 4 | | |
| | | 5 | | /// <summary> |
| | | 6 | | /// A readonly immutable generic dictionary of non-null keys and values which performs equality by value. |
| | | 7 | | /// </summary> |
| | | 8 | | /// <typeparam name="TKey">The type of keys in the dictionary.</typeparam> |
| | | 9 | | /// <typeparam name="TValue">The type of values in the dictionary.</typeparam> |
| | | 10 | | /// <remarks> |
| | | 11 | | /// Immutability can be guaranteed by cloning the provided dictionary and exposing a readonly view of it, but only |
| | | 12 | | /// if immutability of underlying <typeparamref name="TKey"/> and <typeparamref name="TValue"/> is provided, for |
| | | 13 | | /// example, by using immutable records. |
| | | 14 | | /// </remarks> |
| | | 15 | | public class ValueReadOnlyDictionary<TKey, TValue> : ReadOnlyDictionary<TKey, TValue> |
| | | 16 | | where TKey : notnull |
| | | 17 | | where TValue : notnull |
| | | 18 | | { |
| | | 19 | | /// <summary> |
| | | 20 | | /// Creates value readonly dictionary out of the provided dictionary, and independent from it. |
| | | 21 | | /// </summary> |
| | | 22 | | /// <param name="dictionary">The dictionary to be used to build the readonly dictionary.</param> |
| | | 23 | | public ValueReadOnlyDictionary(IDictionary<TKey, TValue> dictionary) |
| | 125057 | 24 | | : base(new Dictionary<TKey, TValue>(dictionary)) |
| | 125057 | 25 | | { |
| | 125057 | 26 | | } |
| | | 27 | | |
| | | 28 | | /// <summary> |
| | | 29 | | /// Creates value readonly dictionary out of the provided entries, and independent from the provided |
| | | 30 | | /// enumerable of them. |
| | | 31 | | /// </summary> |
| | | 32 | | /// <param name="entries">The enumerable of entries to be used to build the readonly dictionary.</param> |
| | | 33 | | |
| | | 34 | | public ValueReadOnlyDictionary(IEnumerable<KeyValuePair<TKey, TValue>> entries) |
| | 3 | 35 | | : base(new Dictionary<TKey, TValue>(entries)) |
| | 3 | 36 | | { |
| | 3 | 37 | | } |
| | | 38 | | |
| | | 39 | | /// <inheritdoc path="//*[not(self::summary or self::remarks)]"/> |
| | | 40 | | /// <summary> |
| | | 41 | | /// <inheritdoc/> |
| | | 42 | | /// <br/> |
| | | 43 | | /// Equality is calculated by value, i.e. on the dictionary key-value pairs directly. |
| | | 44 | | /// </summary> |
| | | 45 | | /// <remarks> |
| | | 46 | | /// Two dictionaries are considered equal by value if: |
| | | 47 | | /// <br/> |
| | | 48 | | /// - they have the same set of keys |
| | | 49 | | /// <br/> |
| | | 50 | | /// - and the value associated, with each of the key by the two dictionaries are equal with each other. |
| | | 51 | | /// </remarks> |
| | | 52 | | public override bool Equals(object? obj) => |
| | 1064 | 53 | | obj is ValueReadOnlyDictionary<TKey, TValue> other && |
| | 1064 | 54 | | Count == other.Count && |
| | 1064 | 55 | | Keys.ToHashSet().SetEquals(other.Keys.ToHashSet()) && |
| | 1922 | 56 | | Keys.All(k => Equals(this[k], other[k])); |
| | | 57 | | |
| | | 58 | | /// <inheritdoc path="//*[not(self::summary)]"/> |
| | | 59 | | /// <summary> |
| | | 60 | | /// <inheritdoc/> |
| | | 61 | | /// <br/> |
| | | 62 | | /// The hash code is calculated by value, as an aggregate of the hash codes of its key value pairs. |
| | | 63 | | /// </summary> |
| | | 64 | | public override int GetHashCode() => |
| | 4486 | 65 | | this.Select(kvp => kvp.GetHashCode()).Aggregate(0.GetHashCode(), (acc, v) => acc ^ v); |
| | | 66 | | |
| | | 67 | | /// <inheritdoc path="//*[not(self::summary)]"/> |
| | | 68 | | /// <summary> |
| | | 69 | | /// <inheritdoc/> |
| | | 70 | | /// <br/> |
| | | 71 | | /// Format: "{[k1] = v1, [k2] = v2, ...}". |
| | | 72 | | /// </summary> |
| | | 73 | | public override string ToString() => |
| | 3 | 74 | | $"{{{string.Join(", ", this.Select(kvp => $"[{kvp.Key}] = {kvp.Value}"))}}}"; |
| | | 75 | | |
| | | 76 | | /// <summary> |
| | | 77 | | /// Compare the two provided value read-only dictionaries for equality by value. |
| | | 78 | | /// </summary> |
| | | 79 | | /// <param name="left">The first term of comparison.</param> |
| | | 80 | | /// <param name="right">The second term of comparison.</param> |
| | | 81 | | /// <returns>True if the two dictionaries are equal by their items, false otherwise.</returns> |
| | | 82 | | public static bool operator ==( |
| | | 83 | | ValueReadOnlyDictionary<TKey, TValue> left, ValueReadOnlyDictionary<TKey, TValue> right) => |
| | 3 | 84 | | Equals(left, right); |
| | | 85 | | |
| | | 86 | | /// <summary> |
| | | 87 | | /// Compare the two provided value read-only dictionaries for inequality by value. |
| | | 88 | | /// </summary> |
| | | 89 | | /// <param name="left">The first term of comparison.</param> |
| | | 90 | | /// <param name="right">The second term of comparison.</param> |
| | | 91 | | /// <returns>True if the two dictionaries are different by their items, false otherwise.</returns> |
| | | 92 | | public static bool operator !=( |
| | | 93 | | ValueReadOnlyDictionary<TKey, TValue> left, ValueReadOnlyDictionary<TKey, TValue> right) => |
| | 3 | 94 | | !Equals(left, right); |
| | | 95 | | } |