Add LocalizedDatasetPrototype (#28310)

Content.Shared/Dataset/LocalizedDatasetPrototype.cs

@@ -0,0 +1,94 @@
+using System.Collections;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Dataset;
+
+/// <summary>
+/// A variant of <see cref="DatasetPrototype"/> intended to specify a sequence of LocId strings
+/// without having to copy-paste a ton of LocId strings into the YAML.
+/// </summary>
+[Prototype]
+public sealed partial class LocalizedDatasetPrototype : IPrototype
+{
+    /// <summary>
+    /// Identifier for this prototype.
+    /// </summary>
+    [ViewVariables]
+    [IdDataField]
+    public string ID { get; private set; } = default!;
+
+    /// <summary>
+    /// Collection of LocId strings.
+    /// </summary>
+    [DataField]
+    public LocalizedDatasetValues Values { get; private set; } = [];
+}
+
+[Serializable, NetSerializable]
+[DataDefinition]
+public sealed partial class LocalizedDatasetValues : IReadOnlyList<string>
+{
+    /// <summary>
+    /// String prepended to the index number to generate each LocId string.
+    /// For example, a prefix of <c>tips-dataset-</c> will generate <c>tips-dataset-1</c>,
+    /// <c>tips-dataset-2</c>, etc.
+    /// </summary>
+    [DataField(required: true)]
+    public string Prefix { get; private set; } = default!;
+
+    /// <summary>
+    /// How many values are in the dataset.
+    /// </summary>
+    [DataField(required: true)]
+    public int Count { get; private set; }
+
+    public string this[int index]
+    {
+        get
+        {
+            if (index > Count || index < 0)
+                throw new IndexOutOfRangeException();
+            return Prefix + index;
+        }
+    }
+
+    public IEnumerator<string> GetEnumerator()
+    {
+        return new Enumerator(this);
+    }
+
+    IEnumerator IEnumerable.GetEnumerator()
+    {
+        return GetEnumerator();
+    }
+
+    public sealed class Enumerator : IEnumerator<string>
+    {
+        private int _index = 0; // Whee, 1-indexing
+
+        private readonly LocalizedDatasetValues _values;
+
+        public Enumerator(LocalizedDatasetValues values)
+        {
+            _values = values;
+        }
+
+        public string Current => _values.Prefix + _index;
+
+        object IEnumerator.Current => Current;
+
+        public void Dispose() { }
+
+        public bool MoveNext()
+        {
+            _index++;
+            return _index <= _values.Count;
+        }
+
+        public void Reset()
+        {
+            _index = 0;
+        }
+    }
+}