Unity Project

reference
https://cardgames.io/yahtzee/

Library/PackageCache/com.unity.textmeshpro@2.0.1/Scripts/Runtime/TMP_InputValidator.cs

@@ -0,0 +1,15 @@
+using UnityEngine;
+using System.Collections;
+
+
+namespace TMPro
+{
+    /// <summary>
+    /// Custom text input validator where user can implement their own custom character validation.
+    /// </summary>
+    [System.Serializable]
+    public abstract class TMP_InputValidator : ScriptableObject
+    {
+        public abstract char Validate(ref string text, ref int pos, char ch);
+    }
+}