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@hax
hax / index.js
Created September 1, 2022 10:57
JS trick to mimic C# obj.onevent += delegate
const HandlerID = Symbol()
export function defineEvent(obj, name) {
const handlers = new Set()
const fn = function () {
for (const handler of handlers) {
try {
handler()
} catch (e) {
Promise.reject(e)
@sindresorhus
sindresorhus / esm-package.md
Last active July 14, 2025 05:53
Pure ESM package

Pure ESM package

The package that linked you here is now pure ESM. It cannot be require()'d from CommonJS.

This means you have the following choices:

  1. Use ESM yourself. (preferred)
    Use import foo from 'foo' instead of const foo = require('foo') to import the package. You also need to put "type": "module" in your package.json and more. Follow the below guide.
  2. If the package is used in an async context, you could use await import(…) from CommonJS instead of require(…).
  3. Stay on the existing version of the package until you can move to ESM.
@AndyShiue
AndyShiue / CuTT.md
Last active July 4, 2025 05:39
Cubical type theory for dummies

I think I’ve figured out most parts of the cubical type theory papers; I’m going to take a shot to explain it informally in the format of Q&As. I prefer using syntax or terminologies that fit better rather than the more standard ones.

Q: What is cubical type theory?

A: It’s a type theory giving homotopy type theory its computational meaning.

Q: What is homotopy type theory then?

A: It’s traditional type theory (which refers to Martin-Löf type theory in this Q&A) augmented with higher inductive types and the univalence axiom.

In JavaScript, all binding declarations are instantiated when control flow enters the scope in which they appear. Legacy var and function declarations allow access to those bindings before the actual declaration, with a "value" of undefined. That legacy behavior is known as "hoisting". let and const binding declarations are also instantiated when control flow enters the scope in which they appear, with access prevented until the actual declaration is reached; this is called the Temporal Dead Zone. The TDZ exists to prevent the sort of bugs that legacy hoisting can create.

@pelotom
pelotom / existential.ts
Last active February 21, 2025 09:21
Encoding of existential types in TypeScript
type StackOps<S, A> = {
init(): S
push(s: S, x: A): void
pop(s: S): A
size(s: S): number
}
type Stack<A> = <R>(go: <S>(ops: StackOps<S, A>) => R) => R
const arrayStack = <A>(): Stack<A> =>
@kencoba
kencoba / sf_1.v
Created April 21, 2011 08:15
Software Foundations exercises
Inductive day : Type :=
| monday : day
| tuesday : day
| wednesday : day
| thursday : day
| friday : day
| saturday : day
| sunday : day.
Definition next_weekday (d:day) : day :=