update doc

Author: NotFounds(iori)

collections/README.md

@@ -397,16 +397,21 @@ console.assert(
 
 ### single
 
-Returns the value if the given array matching the given predicate exactly once.
+Returns the only element in the given collection matching the given predicate.
+Returns undefined if there is none.
 
 ```ts
-import { single } from "./single.ts";
-import { assertEquals } from "../testing/asserts.ts";
+import { single } from "https://deno.land/std@$STD_VERSION/collections/mod.ts";
+import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts";
 
-const numbers = [ 4, 2, 7, 6 ];
-const match = single(numbers, it => it % 2 === 1)
+const bookings = [
+    { month: 'January', active: false },
+    { month: 'March', active: false },
+    { month: 'June', active: true },
+];
+const activeBooking = single(bookings, (it) => it.active);
 
-assertEquals(match, 6);
+assertEquals(activeBooking, { month: 'June', active: true });
 ```
 
 ### sortBy

collections/single.ts

@@ -1,18 +1,22 @@
 // Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
 
 /**
- * Returns the value if the given array matching the given predicate exactly once
+ * Returns the only element in the given collection matching the given predicate. Returns undefined if there is none.
  *
  * Example:
  *
  * ```ts
  * import { single } from "./single.ts";
  * import { assertEquals } from "../testing/asserts.ts";
  *
- * const numbers = [ 4, 2, 7, 6 ];
- * const match = single(numbers, it => it % 2 === 1);
+ * const bookings = [
+ *     { month: 'January', active: false },
+ *     { month: 'March', active: false },
+ *     { month: 'June', active: true },
+ * ];
+ * const activeBooking = single(bookings, (it) => it.active);
  *
- * assertEquals(match, 6);
+ * assertEquals(activeBooking, { month: 'June', active: true });
  * ```
  */
 export function single<T>(