planning

node_modules/@emotion/weak-memoize/src/index.ts

@@ -0,0 +1,17 @@
+let weakMemoize = function <Arg extends object, Return>(
+  func: (arg: Arg) => Return
+): (arg: Arg) => Return {
+  let cache = new WeakMap<Arg, Return>()
+  return (arg: Arg) => {
+    if (cache.has(arg)) {
+      // Use non-null assertion because we just checked that the cache `has` it
+      // This allows us to remove `undefined` from the return value
+      return cache.get(arg)!
+    }
+    let ret = func(arg)
+    cache.set(arg, ret)
+    return ret
+  }
+}
+
+export default weakMemoize