incremental-alphabet

A tiny, dependency-free generator for incremental strings:

a, b, c, ... z, aa, ab, ac, ...

Installation

npm install incremental-alphabet

Usage

import { IncrementalAlphabet } from "incremental-alphabet";

const incrementalAlphabet = new IncrementalAlphabet();

incrementalAlphabet.next(); // "a"
incrementalAlphabet.next(); // "b"
incrementalAlphabet.next(); // "c"

The generator continues after z with aa, ab, ac, and so on. Each instance keeps its own position in memory.

Custom alphabet

Pass a string to the constructor to control the characters and their order:

const binary = new IncrementalAlphabet("01");

binary.next(); // "0"
binary.next(); // "1"
binary.next(); // "00"
binary.next(); // "01"

The alphabet must contain at least one character. Unicode characters, including emoji, are supported.

Iteration

IncrementalAlphabet implements JavaScript's iterable protocol, so it can be used anywhere an iterator is accepted:

const ids = new IncrementalAlphabet();

for (const id of ids) {
	console.log(id);

	if (id === "ac") break;
}

The iterator is infinite, so make sure the consuming code has a stopping condition.

API

new IncrementalAlphabet(alphabet?)

Creates a new generator. alphabet defaults to the lowercase English alphabet (abcdefghijklmnopqrstuvwxyz).

incrementalAlphabet.next()

Returns the next string and advances the generator.

Development

pnpm install
pnpm test
pnpm run typecheck
pnpm run pack:dry-run

License

MIT