restructure fs

lang/Nub.Lang/Optional.cs

@@ -0,0 +1,48 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace Nub.Lang;
+
+public readonly struct Optional
+{
+    public static Optional<TValue> Empty<TValue>() => new();
+
+    /// <summary>
+    /// Alias for creating an Optional&lt;TValue&gt; which allows for implicit types
+    /// </summary>
+    /// <param name="value"></param>
+    /// <typeparam name="TValue"></typeparam>
+    /// <returns></returns>
+    public static Optional<TValue> OfNullable<TValue>(TValue? value)
+    {
+        return value ?? Optional<TValue>.Empty();
+    }
+}
+
+public readonly struct Optional<TValue>
+{
+    public static Optional<TValue> Empty() => new();
+
+    public static Optional<TValue> OfNullable(TValue? value)
+    {
+        return value ?? Empty();
+    }
+
+    public Optional()
+    {
+        Value = default;
+        HasValue = false;
+    }
+
+    public Optional(TValue value)
+    {
+        Value = value;
+        HasValue = true;
+    }
+
+    public TValue? Value { get; }
+
+    [MemberNotNullWhen(true, nameof(Value))]
+    public bool HasValue { get; }
+
+    public static implicit operator Optional<TValue>(TValue value) => new(value);
+}