@pvorona/counter

A tiny mutable counter.

Install

npm i @pvorona/counter

Usage

import { createCounter } from '@pvorona/counter';

const counter = createCounter(5);

counter.value; // 5
counter.increment(); // 6
counter.set(20); // 20
counter.reset(); // 5
counter.value; // 5

API

type Counter

Public counter interface.

export type Counter = {
  readonly value: number;
  increment(amount?: number): number;
  decrement(amount?: number): number;
  set(value: number): number;
  reset(): number;
};

Notes:

• value is the current count.
• increment(amount?) adds amount (defaults to 1) and returns the updated value.
• decrement(amount?) subtracts amount (defaults to 1) and returns the updated value.
• set(value) replaces the current value and returns it.
• reset() restores the original initialValue and returns it.

Example:

import type { Counter } from '@pvorona/counter';

function reset(counter: Counter) {
  counter.reset();
}

createCounter(initialValue?: number): Counter

Creates a new counter.

• initialValue: starting value (defaults to 0)
• returns: a Counter

Example:

import { createCounter } from '@pvorona/counter';

const clicks = createCounter();
clicks.increment(); // 1