Like Scheme boxes but for TypeScript
npm install ts-boxedLike Scheme's boxes but for TypeScript.
``typescript`
unbox(box(myObj)) === myObj
Why do you need this? You probably don't. If you've ever wanted JS to have
pointers to pointers or out parameters, boxes can help.
`
npm i ts-boxed
Boxes are mutable references to a single value.
`typescript
import { box, unbox, setBox$ } from 'ts-boxed';
// Unboxing gets the original value (reference equality)...
const myObj = {};
unbox(box(myObj)) === myObj;
// without mutating the box.
const myBox = box('contents');
unbox(myBox) === 'contents';
unbox(myBox) === 'contents'; // still true
// Like Scheme, the setter has scary punctuation (too bad set-box! isn't a valid JS identifier).`
setBox$(myBox, '2');
unbox(myBox) === '2';
setBox$(myBox, '3');
unbox(myBox) === '3';
isBox is a runtime check but also provides type information
to TypeScript.
`typescriptBox
function f(maybeBox: unknown) {
if (isBox(maybeBox)) {
// maybeBox now has type
unbox(maybeBox);
} else {
// @ts-ignore maybeBox still has type
unbox(maybeBox);
}
}