base32 refactoring

Core/Collections/ImmutableSequence.cs

@@ -3,6 +3,22 @@ using System.Collections.Immutable;
 
 namespace Just.Core.Collections;
 
+/// <summary>
+/// Represents an immutable, ordered sequence of items with value‑equality semantics.
+/// </summary>
+/// <typeparam name="T">The type of elements in the sequence.</typeparam>
+/// <remarks>
+/// <para>
+/// This class is a thin wrapper around <see cref="ImmutableList{T}"/> that implements
+/// <see cref="IReadOnlyList{T}"/>, <see cref="IEquatable{T}"/>, and value‑based equality.
+/// All modifications return new <see cref="ImmutableSequence{T}"/> instances, leaving the
+/// original unchanged.
+/// </para>
+/// <para>
+/// Subclasses may override <see cref="ConstructNew"/> to ensure mutation methods return
+/// the correct derived type.
+/// </para>
+/// </remarks>
 public class ImmutableSequence<T> :
     IEnumerable<T>,
     IReadOnlyList<T>,
@@ -11,17 +27,61 @@ public class ImmutableSequence<T> :
     private static readonly Func<T?, T?, bool> CompareItem = EqualityComparer<T>.Default.Equals;
     private readonly ImmutableList<T> _values;
 
+    /// <summary>
+    /// Initializes a new empty instance of the <see cref="ImmutableSequence{T}"/> class.
+    /// </summary>
     public ImmutableSequence() => _values = [];
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImmutableSequence{T}"/> class that
+    /// wraps the specified <see cref="ImmutableList{T}"/>.
+    /// </summary>
+    /// <param name="values">The immutable list to wrap.</param>
     public ImmutableSequence(ImmutableList<T> values) => _values = values;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImmutableSequence{T}"/> class with
+    /// the elements from the provided enumerable sequence.
+    /// </summary>
+    /// <param name="values">The items to include in the sequence.</param>
     public ImmutableSequence(IEnumerable<T> values) => _values = [..values];
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImmutableSequence{T}"/> class with
+    /// the elements from the provided read‑only span.
+    /// </summary>
+    /// <param name="values">The items to include in the sequence.</param>
     public ImmutableSequence(ReadOnlySpan<T> values) : this(ImmutableList.Create(values))
     {
     }
 
+    /// <summary>
+    /// Gets a value indicating whether the sequence contains any elements.
+    /// </summary>
     public bool IsEmpty => _values.IsEmpty;
+
+    /// <summary>
+    /// Gets the number of elements in the sequence.
+    /// </summary>
     public int Count => _values.Count;
+
+    /// <summary>
+    /// Gets the element at the specified zero‑based index.
+    /// </summary>
+    /// <param name="index">The zero‑based index of the element to get.</param>
+    /// <returns>The element at the specified index.</returns>
     public T this[int index] => _values[index];
+    /// <summary>
+    /// Gets the element at the specified position from the start or end of the sequence.
+    /// </summary>
+    /// <param name="index">An <see cref="Index"/> value (e.g., <c>^1</c> for the last element).</param>
+    /// <returns>The element at the specified position.</returns>
     public T this[Index index] => _values[index];
+    /// <summary>
+    /// Gets a new <see cref="ImmutableSequence{T}"/> containing the elements in the specified range.
+    /// </summary>
+    /// <param name="range">The range of elements to include.</param>
+    /// <returns>A new sequence representing the slice.</returns>
     public ImmutableSequence<T> this[Range range]
     {
         get
@@ -31,25 +91,60 @@ public class ImmutableSequence<T> :
         }
     }
 
+    /// <summary>
+    /// Creates a new <see cref="ImmutableSequence{T}"/> from the provided immutable list.
+    /// Subclasses can override this to return instances of a more specific type.
+    /// </summary>
+    /// <param name="values">The immutable list that will become the internal storage.</param>
+    /// <returns>A new sequence containing the given items.</returns>
     protected virtual ImmutableSequence<T> ConstructNew(ImmutableList<T> values) => [..values];
 
+    /// <summary>
+    /// Returns a new sequence with the specified value appended to the end.
+    /// </summary>
+    /// <param name="value">The value to add.</param>
+    /// <returns>A new sequence containing the original items followed by <paramref name="value"/>.</returns>
     public ImmutableSequence<T> Add(T value) => ConstructNew(_values.Add(value));
+    /// <summary>
+    /// Returns a new sequence with the specified value inserted at the beginning.
+    /// </summary>
+    /// <param name="value">The value to add.</param>
+    /// <returns>A new sequence that starts with <paramref name="value"/> and then contains the original items.</returns>
     public ImmutableSequence<T> AddFront(T value) => ConstructNew(_values.Insert(0, value));
 
+    /// <summary>
+    /// Returns an enumerator that iterates through the sequence.
+    /// </summary>
+    /// <returns>A <see cref="ImmutableList{T}.Enumerator"/> value type enumerator.</returns>
     public ImmutableList<T>.Enumerator GetEnumerator() => _values.GetEnumerator();
     IEnumerator<T> IEnumerable<T>.GetEnumerator() => ((IEnumerable<T>)_values).GetEnumerator();
     IEnumerator IEnumerable.GetEnumerator() => ((IEnumerable)_values).GetEnumerator();
 
     public override string ToString() => string.Join(Environment.NewLine, _values);
 
+    /// <summary>
+    /// Determines whether this sequence is equal to another <see cref="ImmutableSequence{T}"/>.
+    /// Equality is based on the number of elements and the element‑wise equality comparison
+    /// using the default equality comparer for <typeparamref name="T"/>.
+    /// </summary>
+    /// <param name="other">The sequence to compare with this instance. Can be <c>null</c>.</param>
+    /// <returns>
+    /// <c>true</c> if the sequences have the same length and all elements are equal;
+    /// <c>false</c> otherwise.
+    /// </returns>
     public virtual bool Equals([NotNullWhen(true)] ImmutableSequence<T>? other)
     {
+        if (other is null)
+        {
+            return false;
+        }
+
         if (ReferenceEquals(this, other))
         {
             return true;
         }
 
-        if (_values.Count != other?._values.Count)
+        if (_values.Count != other._values.Count)
         {
             return false;
         }
@@ -65,7 +160,16 @@ public class ImmutableSequence<T> :
         return true;
     }
 
+    /// <summary>
+    /// Determines whether the specified object is equal to the current sequence.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current sequence.</param>
+    /// <returns><c>true</c> if <paramref name="obj"/> is an <see cref="ImmutableSequence{T}"/> and equals this instance; otherwise <c>false</c>.</returns>
     public override bool Equals([NotNullWhen(true)] object? obj) => Equals(obj as ImmutableSequence<T>);
+    /// <summary>
+    /// Serves as a hash function for the sequence.
+    /// </summary>
+    /// <returns>A hash code that incorporates all elements in order.</returns>
     public override int GetHashCode()
     {
         HashCode hash = new();
@@ -78,6 +182,18 @@ public class ImmutableSequence<T> :
         return hash.ToHashCode();
     }
 
+    /// <summary>
+    /// Determines whether two sequences are equal.
+    /// </summary>
+    /// <param name="left">The first sequence to compare.</param>
+    /// <param name="right">The second sequence to compare.</param>
+    /// <returns><c>true</c> if both sequences are <c>null</c> or they are considered equal; otherwise <c>false</c>.</returns>
     public static bool operator ==(ImmutableSequence<T>? left, ImmutableSequence<T>? right) => left is null ? right is null : left.Equals(right);
+    /// <summary>
+    /// Determines whether two sequences are not equal.
+    /// </summary>
+    /// <param name="left">The first sequence to compare.</param>
+    /// <param name="right">The second sequence to compare.</param>
+    /// <returns><c>true</c> if the sequences are not equal; otherwise <c>false</c>.</returns>
     public static bool operator !=(ImmutableSequence<T>? left, ImmutableSequence<T>? right) => !(left == right);
 }