From e220b7930cea8fb8777469e859b8a6a3d258d1b7 Mon Sep 17 00:00:00 2001
From: Eric Rumsey <ehrumsey@gmail.com>
Date: Thu, 29 May 2025 11:39:33 -0500
Subject: [PATCH] Add Tag type and hasTag function

---
 src/lib/util/basic/utility.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/lib/util/basic/utility.ts b/src/lib/util/basic/utility.ts
index 4cdee12..309f373 100644
--- a/src/lib/util/basic/utility.ts
+++ b/src/lib/util/basic/utility.ts
@@ -174,5 +174,11 @@ export const tryCatch = <A>(f: () => A): Either<A, Error> => {
   }
 }
 
+export interface Tag<T> {
+  readonly _tag: T
+}
+
+export const hasTag = (x: string) => (y: Tag<string>) => x === y._tag
+
 export const fromNullable = <A>(a: A | null | undefined): Option<A> =>
   a == null ? none : some(a)