feat: temporary grammar

InkBlot/Helpers.cs

@@ -0,0 +1,18 @@
+using System.Diagnostics;
+
+namespace InkBlot;
+
+public static class Helpers
+{
+    public static T AsNotNull<T>(this T? value) where T : struct
+    {
+        Debug.Assert(value.HasValue);
+        return value.Value;
+    }
+
+    public static T AsNotNull<T>(this T? value) where T : class
+    {
+        Debug.Assert(value != null);
+        return value;
+    }
+}