Utils

range

An iterable generator for creating numeric sequences.

The range utility creates a lightweight iterable object that generates a sequence of numbers. Because it uses the Symbol.iterator protocol, it is extremely memory-efficient and can be used directly in for...of loops or spread into arrays.

Definition

range.ts

/**
 * Creates an iterable range generator.
 *
 * @param start - The baseline number.
 * @param end - The target end number (inclusive).
 * @param step - The increment step (default: 1).
 * @param inclusiveStart - If true, starts at `start`. If false (default), starts at `start + step`.
 * @returns An iterable object that yields the sequence.
 */
export function range(
    start: number,
    end: number,
    step = 1,
    inclusiveStart = false
): IterableIterator<number>

Parameters

Parameter	Type	Default	Description
`start`	`number`	-	The starting point of the sequence.
`end`	`number`	-	The target end value (inclusive).
`step`	`number`	`1`	The amount to increment by in each step.
`inclusiveStart`	`boolean`	`false`	Whether to include the `start` value as the first element.

Behavior

Incremental: Generates numbers from start to end.
Custom Steps: You can define the gap between numbers using the step parameter.
Inclusive Options: By default, it starts at start + step. Use inclusiveStart: true to begin exactly at the start value.

Example Usage

example.ts

import { range } from '@riavzon/utils'

// 1. Basic usage (1 to 5)
const basic = [...range(0, 5)];
// [1, 2, 3, 4, 5]

// 2. Inclusive start (0 to 5)
const inclusive = [...range(0, 5, 1, true)];
// [0, 1, 2, 3, 4, 5]

// 3. Custom steps (0 to 10 by 2s)
const stepping = [...range(0, 10, 2, true)];
// [0, 2, 4, 6, 8, 10]

// 4. looping
for (const n of range(0, 1000000)) {
  // Loop through a million numbers without creating a massive array in memory
  if (n === 5) break;
}

The step parameter must be greater than 0, otherwise the utility will throw an error to prevent infinite loops.

Random

rateLimiters