From c94ce8c7456eac53f62499aab305b683c4514ca4 Mon Sep 17 00:00:00 2001
From: Xevion <ryanchwalters@gmail.com>
Date: Fri, 24 Feb 2023 20:37:53 -0600
Subject: [PATCH] Add type-safe set functions

---
 src/sets.ts | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 src/sets.ts

diff --git a/src/sets.ts b/src/sets.ts
new file mode 100644
index 0000000..517c391
--- /dev/null
+++ b/src/sets.ts
@@ -0,0 +1,13 @@
+export const union = <T>(a: Set<T>, b: Set<T>) => new Set([...a, ...b]);
+export const intersection = <T>(a: Set<T>, b: Set<T>) =>
+	new Set([...a].filter((x) => b.has(x)));
+export const difference = <T>(a: Set<T>, b: Set<T>) =>
+	new Set([...a].filter((x) => !b.has(x)));
+export const symmetric = <T>(a: Set<T>, b: Set<T>) =>
+	union(difference(a, b), difference(b, a));
+export const isSubsetOf = <T>(a: Set<T>, b: Set<T>) =>
+	[...b].every((x) => a.has(x));
+export const isSupersetOf = <T>(a: Set<T>, b: Set<T>) =>
+	[...a].every((x) => b.has(x));
+export const isDisjointFrom = <T>(a: Set<T>, b: Set<T>) =>
+	!intersection(a, b).size;