Crypto._randomString() + Crypto._randomDictBaseX

In theory, you should just use Crypto.randomUUID() or Crypto.randomBytes(16).toString('base64'), but due to nuance differences in desires, people end up re-implementing a randomString() function.

Making this simpler may not actually fix that - people like to re-invent well-known wheels.

However, it should help those who subscribe to AjScript to have it ready-at-hand.

let rnd = Crypto._randomString(len, [dict]);

// crockford base32
Crypto._randomDictBase32 = "0123456789ABCDEFGHJKMNPQRSTVWXYZ"

// bc base58x
Crypto._randomDictBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"

// gh base62 (alphanumeric)
Crypto._randomDictBase62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

// base64 (silly, but convenient. TODO rename 'Base64Unsafe'?)
Crypto._randomDictBase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

// urlsafe-base64 (TODO: name?)
Crypto._randomDictBase64Url = Crypto._randomDictBase64.slice(-2) + '-_';

How to pass custom dictionary / charset?

Optional name? or optional dict?

let rnd = Crypto._randomString(len, 'base32');

let myDict = "ABC123...".split('')
let rnd = Crypto._randomString(let, myDict);

I'm leaning toward this:

let myDict = "ABC123...".split('')
let rnd = Crypto._randomString(len, 'base58', myDict);

char len vs entropy

Hmm...

I'm leaning towards len meaning number of string characters, as this seems most intuitive.

There may need to be a Crypto._bitsPerChar(len) and Crypto._minCharsForBits(256) or some such.

See https://therootcompany.com/blog/how-many-bits-of-entropy-per-character/.

sync vs async?

Typically the strings people want are small - 32 bytes (256-bit entropy) or less, which points to a synchronous function being the most optimal, and I think even the browser getRandomValues is synchronous.

GPTScript / AiScript