refactor

src/random.ts

@@ -1,19 +1,11 @@
 import { BitArray } from "./bitarray.js";
 import { asArray } from "./utils.js";
 
-export interface ElementPredicate<T = any> {
-  (index: number, obj: T): boolean;
-}
+export type ElementPredicate<T = any> = (index: number, obj: T) => boolean;
+export type ElementWeight<T = any> = (index: number, obj: T) => number;
+export type RandomGenerator = () => number;
 
-export interface ElementWeight<T = any> {
-  (index: number, obj: T): number;
-}
-
-export interface RandomGenerator {
-  (): number;
-}
-
-export interface RandomOptions<T> {
+export interface RandomOptions<T = any> {
   predicate?: ElementPredicate<T>;
   weight?: ElementWeight<T>;
   random?: RandomGenerator;
@@ -23,7 +15,7 @@ export const alwaysTrue: ElementPredicate = () => true;
 export const weightOfOne: ElementWeight = () => 1.0;
 export const mathRandom: RandomGenerator = () => Math.random();
 
-const defaultOptions = Object.freeze<Required<RandomOptions<any>>>({
+const defaultOptions = Object.freeze<Required<RandomOptions>>({
   predicate: alwaysTrue,
   weight: weightOfOne,
   random: mathRandom
@@ -50,7 +42,7 @@ function mergeOptions<T>(first: RandomOptions<T> | undefined, second: RandomOpti
 
 function withDefaultOptions<T>(options: RandomOptions<T> | undefined): Required<RandomOptions<T>> {
   if (!options) {
-    return { ...defaultOptions };
+    return defaultOptions;
   }
 
   return {
@@ -98,7 +90,7 @@ export class RandomPicker<T> {
   public constructor(elements: T[], options?: RandomOptions<T>) {
     this.#elements = elements;
     this.#flags = new BitArray(elements.length);
-    this.#options = withDefaultOptions(mergeOptions({ predicate: (i, o) => this.#flags.get(i) }, options));
+    this.#options = withDefaultOptions(mergeOptions({ predicate: i => this.#flags.get(i) }, options));
 
     this.reset();
   }