https://github.com/bwireman/delay
A dead simple data-structure for delaying side effects. Written in the excellent gleam language. Available on the Beam & in the browser!
https://github.com/bwireman/delay
bun delay deno elixir erlang gleam javascript monad nodejs sideeffects
Last synced: 7 months ago
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A dead simple data-structure for delaying side effects. Written in the excellent gleam language. Available on the Beam & in the browser!
- Host: GitHub
- URL: https://github.com/bwireman/delay
- Owner: bwireman
- License: mit
- Created: 2021-08-18T01:29:49.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2024-12-04T01:14:36.000Z (7 months ago)
- Last Synced: 2024-12-04T02:22:41.522Z (7 months ago)
- Topics: bun, delay, deno, elixir, erlang, gleam, javascript, monad, nodejs, sideeffects
- Language: Gleam
- Homepage: https://hexdocs.pm/delay/index.html
- Size: 280 KB
- Stars: 6
- Watchers: 2
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-gleam - delay - [📚](https://hexdocs.pm/delay/) - A dead simple data-structure for delaying side effects (Packages / Data Structures)
README
# Delay ⌚
A dead simple data-structure for delaying side effects ⌚! Written in the excellent [gleam ✨](https://gleam.run/) language. Supporting both Erlang & Javascript targets
[](https://github.com/bwireman/delay/actions/workflows/test.yml)
[](https://github.com/bwireman/delay/commit/main)
[](https://github.com/bwireman/delay/blob/main/LICENSE)
[](http://makeapullrequest.com)
[](https://hexdocs.pm/delay/index.html)
[](https://gleam.run)
[](https://hex.pm/packages/delay/)
[](https://gleam.run/news/v0.16-gleam-compiles-to-javascript/)
[](https://www.npmjs.com/package/delay-gleam)
## Basic Usage
```gleam
import gleam/io
import delay
let d = delay.delay_effect(fn() {
io.println("Hello")
Ok(1)
}) |> delay.map(fn(x) {
io.println("World")
Ok(x + 1)
})
let res = delay.run(d)
// Hello
// World
// res = Ok(2)
```
## More info
The result of `delay_effect` is really just a first class function with a nice API wrapper. It isn't executed until put through one of `run/1`, `drain/1`, `fallthrough/1` or one of the other functions in order to execute a delayed effect. And can be called as many times as you want.
```gleam
import gleam/io
import delay
let d = delay.delay_effect(fn() {
io.println("Hello")
Error("bummer")
}) |> delay.map(fn(x) {
io.println("World")
Ok(x + 1)
})
let res = delay.run(d)
// Hello
// res = Error("bummer")
```
If one of the functions in the chain fails, the rest will short circuit and the error will be returned.
Effects can be retried as well via `retry/3`
```gleam
// using the same effect `d` from above
let res = delay.retry(d, 3, 200)
|> delay.run()
// Hello
// Hello
// Hello
// Hello
// res = Error("bummer")
```
## Usage within Javascript 🌸 directly
If you want to use this library from javascript alone, but aren't ready to embrace gleam, you can install it from [npm](https://www.npmjs.com/package/delay-gleam)!
Docs can be found [here](https://hexdocs.pm/delay/index.html)
```sh
npm i delay-gleam
```
```javascript
import { delay_effect, map, run } from "delay-gleam"
import { ok, error, get } from "delay-gleam/extras"
d = delay_effect(() => error(console.log("123")))
d = map(d, (_) => ok(console.log("456")))
get(run(d))
// 123
```
### Extras
Helper functions for using this library directly in javascript can be found [here](/dist/extras/extras.mjs)
## FAQ
Doesn't the concept of a delayed side effect kind of lose value in the world of actor model concurrency and zero shared memory?!
> A little
Then why did you write this?
> For fun
Is gleam ✨ actually excellent?
> So far