1 files changed, 22 insertions, 0 deletions
diff --git a/src/utils/adt.ts b/src/utils/adt.ts
index 45d9e50..3ae387c 100644
--- a/src/utils/adt.ts
+++ b/src/utils/adt.ts
@@ -7,6 +7,28 @@ export const match = <R, T extends Tag<string, any>>(
   },
 ): R => ((pattern as any)[tag.tag] || (pattern._ as any))(tag.value)
 
+// type TagValues<
+//   T extends Tag<any, string>,
+//   Keys extends Array<string>,
+//   Values extends Array<any> = [],
+// > = Keys extends []
+//   ? Values
+//   : Keys extends [
+//       infer key extends string,
+//       ...infer restOfKeys extends string[],
+//     ]
+//   ? TagValues<T, restOfKeys, [...Values, TagValue<T, key>]>
+//   : never
+//
+// export const ifLet = <T extends Tag<string, any>, Keys extends Array<T['tag']>>(
+//   tag: T,
+//   kinds: Keys,
+//   cb: (...values: TagValues<T, Keys>) => void,
+// ): void => {
+//   const values = kinds.map(k => (tag.tag === k ? tag.value : undefined))
+//   ;(cb as any)(...values)
+// }
+
 export const matchString = <R, T extends string = string>(
   key: T,
   pattern: {