stz is e280's standard library of environment-agnostic typescript tools. zero dependencies.

ergonomic event emitters

import {pub, sub} from "@e280/stz"

• make a publisher fn

  // create a pub fn
  const sendMessage = pub<[string]>()
  
  // subscribe to it
  sendMessage.subscribe(m => console.log(m))
  
  // publish to it
  sendMessage("hello")

• make a subscriber fn — it's just like pub, except it's flipsy-reversey!

  // create a sub fn
  const onMessage = sub<[string]>()
  
  // subscribe to it
  onMessage(m => console.log(m))
  
  // publish to it
  onMessage.publish("hello")

• pub and sub both have the same facilities
  • .publish
  • .subscribe
  • .on
  • .next
  • .clear
• i seem to use sub more often

• publish actually returns a promise, to wait for all async subscribers

  await onMessage.publish("hello")

• subscribe returns a fn to unsubscribe

  const unsubscribe = onMessage(() => {})
  unsubscribe()

• .clear() to wipe all subscribed listeners

  onMessage.clear()

• .next(fn?) is a better way to do .once..
  • you can use it like a .once:

    onMessage.next(message => {})

  • but it also gives you a promise like this:

    const [message] = await onMessage.next()

  • of course the promise can be used like this:

    onMessage.next().then(([message]) => {})

defer the resolve/reject of a promise to the outside

import {defer} from "@e280/stz"

const deferred = defer()

• resolve the deferred promise

  deferred.resolve()

• reject the deferred promise

  deferred.reject(new Error("fail"))

• await the promise

  await deferred.promise

sleep for some milliseconds

import {nap} from "@e280/stz"

await nap(900)
  // wait for 900 milliseconds

easy trash management

import {disposer} from "@e280/stz"

• create a disposer

  const dispose = disposer()

• schedule something for cleanup

  dispose.schedule(() => console.log("disposed!"))

• schedule multiple things at once

  dispose.schedule(
    () => console.log("disposed thing 1"),
    () => console.log("disposed thing 2"),
    () => ev(window, {keydown: () => console.log("keydown")}),
  )

• schedule is chainable if you prefer that vibe

  dispose
    .schedule(() => console.log("disposed thing 1"))
    .schedule(() => console.log("disposed thing 2"))
    .schedule(() => ev(window, {keydown: () => console.log("keydown")}))

• dispose of all that garbage

  dispose()

extended js data types

extended js Map

• many are saying it's "The Deluxe Mapping Experience"

  import {GMap} from "@e280/stz"
  
  const map = new GMap<number, string>([
    [1, "hello"],
    [2, "world"],
  ])

• map.require(key) — returns the value for key.. if missing, throw an error

  const value = map.require(1)
    // "hello"

• map.guarantee(key, makeFn) — returns the value for key.. if missing, run makeFn to set and return the value

  const value = map.guarantee(3, () => "rofl")
    // "rofl"

extended js Set

• new GSet<T>()
• set.adds(item1, item2, item3) — add multiple items without a for-loop
• set.deletes(item1, item2, item3) — add multiple items without a for-loop

extended js WeakMap

• new GWeakMap<K, V>()
• weakMap.require(key) — returns value for key.. if missing, throw an error
• weakMap.guarantee(key, makeFn) — returns the value for key.. if missing, run makeFn to set and return the value

execute calls in sequence (not concurrent)

import {queue, nap} from "@e280/stz"

const fn = queue(async() => nap(100))

fn()
fn()
await fn() // waits for the previous calls (sequentially)

ensure a fn is only executed one time

import {once} from "@e280/stz"

let count = 0
const fn = once(() => count++)
console.log(count) // 0

fn()
console.log(count) // 1

fn()
console.log(count) // 1

throws an error if the async function takes too long

import {deadline} from "@e280/stz"

const fn = deadline(100, async() => {

  // example deliberately takes too long
  await nap(200)
})

await fn()
  // DeadlineError: deadline exceeded (0.1 seconds)

wait some time before actually executing the fn (absorbing redundant calls)

we use debounce a lot in ui code, like on a user's keyboard input in a form field, but rendering the form input can actually be slow enough that it causes problems when they type fast — to eliminate the jank, we debounce with like 400 ms, so we wait for the user to finish typing for a moment before actually running the validation.

import {debounce} from "@e280/stz"

const fn = debounce(100, async() => {
  await coolAction()
})

// each fn() call resets the timer
fn()
fn()
fn()

// coolAction is only called once here, other calls are redundant

execute a function over and over again, back to back

import {cycle} from "@e280/stz"

let ticks = 0

const stop = cycle(async() => {

  // use a nap to add a delay between each execution
  await nap(200)

  ticks++
})

// stop repeating whenever you want
stop()

convert to/from utf8 string format

• txt.fromBytes(bytes) — bytes to string
• txt.toBytes(string) — string to bytes

utilities for dealing with Uint8Array

• bytes.eq(bytesA, bytesB) — check if two byte arrays are equal
• bytes.random(32) — generate crypto-random bytes

convert binary data to/from various encodings

import {hex, base58, base64} from "@e280/stz"

all BaseX utilities have these methods

• hex.fromBytes(u8array) — encode bytes to string
• hex.toBytes(str) — decode string to bytes
• hex.toInteger(string) — decode string as js integer
• hex.fromInteger(n) — encode js integer as a string
• hex.random(32) — generate random encoded string (32 bytes)

• hex
• base2
• base36
• base58
• base62
• base64
• base64url

• you can provide a lexicon to produce your own BaseX codec

  const myHex = new BaseX({characters: "0123456789abcdef"})

• fun fact: you can make insanely compact timestamp strings like this:

  base62.fromInteger(Date.now() / 1000)
    // "1uK3au"

  • 1748388028 base10 epoch seconds (10 chars)
  • 1uK3au base62 epoch seconds (6 chars)
  • nice

friendly string encoding for binary data

a bytename looks like "midsen.picmyn.widrep.baclut dotreg.filtyp.nosnus.siptev". that's 16 bytes. each byte maps to a three-letter triplet

the bytename parser (bytename.toBytes) ignores all non-alphabetic characters. thus midsen.picmyn, midsenpicmyn, and mid@sen$pic@myn are all equal.

import {bytename} from "@e280/stz"

• bytename.fromBytes(new Uint8Array([0xDE, 0xAD, 0xBE, 0xEF]))
    // "ribmug.hilmun"

• bytename.toBytes("ribmug.hilmun")
    // Uint8Array, 4 bytes

• const data = new Uint8Array([
    0xDE, 0xAD, 0xBE, 0xEF,
    0xDE, 0xAD, 0xBE, 0xEF,
  ])
  
  bytename.fromBytes(data, {
    groupSize: 2, // default is 4
    groupSeparator: " ",
    wordSeparator: ".",
  })
    // "ribmug.hilmun ribmug.hilmun"

hybrid of bytename and base58 to make binary data more human-friendly

• looks like nodlyn.fasrep.habbud.ralwel.Avo7gFmdWMRHkwsD149mcaBoZdS69iXuJ
• the idea is that the first parts are in bytename format, so it's easy for humans to recognize
• and the remaining data is shown in base58
• thumbprint.fromBytes(u8array) — encode bytes to thumbprint string
• thumbprint.toBytes(thumbstring) — decode thumbprint string to bytes
• thumbprint.fromHex(hexstring) — convert a hex string into a thumbprint
• thumbprint.toHex(thumbstring) — convert a thumbprint into a hex string

tar-like binary file format for efficiently packing multiple files together

import {toq, txt} from "@e280/stz"

• 4 magic bytes "TOQ\x01"
• for each file (little endian)
  • name length 1 byte (u8)
  • name x bytes (max 255 B)
  • data length 4 bytes (u32)
  • data x bytes (max 4 GB)

• toq.pack — accepts any iterable of file entries

  const pack: Uint8Array = toq.pack([
    ["hello.txt", txt.toBytes("hello world")],
    ["deadbeef.data", new Uint8Array([0xDE, 0xAD, 0xBE, 0xEF])],
  ])

• toq.is — check if a file is a toq pack or not

  toq.is(pack) // true

• toq.unpack — generator fn yields file entries

  for (const [name, data] of toq.unpack(pack))
    console.log(name, data.length)

• pack a map of files

  const files = new Map<string, Uint8Array>()
  files.set("hello.txt", txt.toBytes("hello world"))
  files.set("deadbeef.data", new Uint8Array([0xDE, 0xAD, 0xBE, 0xEF]))
  
  const pack = toq.pack(files)

• unpack into a new map

  const files = new Map(toq.unpack(pack))

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