Initial sync

Nbt/Tag/NbtValue.cs

@@ -0,0 +1,64 @@
+namespace Nbt.Tag;
+
+public interface INbtValue : INbtTag
+{
+    object Value { get; set; }
+}
+
+public interface INbtValue<T> : INbtValue where T : notnull
+{
+    new T Value { get; set; }
+}
+
+public abstract class NbtValue<T> : INbtValue<T> where T : notnull
+{
+    private static readonly EqualityComparer<T> ValueComparer = EqualityComparer<T>.Default;
+
+    protected T value;
+
+    internal protected NbtValue(T value) : base() => this.value = value;
+
+    public abstract NbtTagType Type { get; }
+
+    INbtTag INbtTag.this[string tagName] { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
+
+    INbtTag INbtTag.this[int tagIndex] { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
+
+    INbtTag INbtTag.this[INbtPathElement tagPath] { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
+
+    INbtList INbtTag.AsList() => throw new NotSupportedException();
+
+    INbtCompound INbtTag.AsCompound() => throw new NotSupportedException();
+
+    INbtValue INbtTag.AsValue() => this;
+
+    INbtValue<U> INbtTag.AsValue<U>() => (INbtValue<U>)this;
+
+    INbtArray INbtTag.AsArray() => (INbtArray)this;
+
+    INbtArray<U> INbtTag.AsArray<U>() => (INbtArray<U>)this;
+
+    INbtTag INbtTag.Copy() => Copy();
+    public NbtValue<T> Copy() => NewInstance(CopyValue());
+
+    object INbtValue.Value
+    {
+        get => Value;
+        set => Value = (T)Convert.ChangeType(value, typeof(T));
+    }
+
+    public T Value
+    {
+        get => value;
+        set => this.value = value ?? throw new ArgumentNullException(nameof(value));
+    }
+
+    protected virtual T CopyValue() => value;
+    protected abstract NbtValue<T> NewInstance(T value);
+
+    public bool Equals(INbtTag? other) => ReferenceEquals(other, this) || other is NbtValue<T> o && ValueComparer.Equals(value, o.value);
+
+    public override bool Equals(object? obj) => ReferenceEquals(obj, this) || obj is NbtValue<T> other && ValueComparer.Equals(value, other.value);
+
+    public override int GetHashCode() => value.GetHashCode();
+}