Damian kraftdorian

```haskell take 16 (cycle "work, ") ```

kraftdorian / reverseString.ts

Created February 20, 2024 18:01

TypeScript utility type to reverse a string

	type Reverse<Input extends string, Acc extends string = ''> =
	Input extends `${infer Head}${infer Tail}`
	? Reverse<Tail, `${Head}${Acc}`>
	: Acc;

	// const o1: Reverse<'SATOR'> = 'ROTAS';
	// const o2: Reverse<'AREPO'> = 'OPERA';
	// const o3: Reverse<'TENET'> = 'TENET';
	// const o4: Reverse<'OPERA'> = 'AREPO';
	// const o5: Reverse<'ROTAS'> = 'SATOR';

kraftdorian / cancelablePromise.js

Last active October 15, 2023 14:21

Cancelable Promise - experiment

	/**
	* @param {AbortSignal} signal
	* @param {(ev: AbortSignalEventMap['abort']) => void} onCancel
	* @returns {() => void}
	*/
	function createSignalCancelListener(signal, onCancel) {
	signal.addEventListener('abort', onCancel);
	return () => signal.removeEventListener('abort', onCancel);
	}

kraftdorian / paginate.js

Last active July 9, 2023 19:07

Static-size items pagination

	// inspired by https://www.zacfukuda.com/blog/pagination-algorithm
	// especialy, the left/right surrounding items idea

	const PaginationItem = {
	PreviousPage: Symbol('PaginationItem.PreviousPage'),
	NextPage: Symbol('PaginationItem.NextPage'),
	};

	function paginate(
	currentPageNumber,

kraftdorian / flatten-2d-list.hs

Last active March 12, 2023 17:34

Transform 2-D array to 1-D array

	flatten2DList :: [[a]] -> [a] -> [a]
	flatten2DList (x:[]) acc = acc ++ x
	flatten2DList (x:xs) acc = flatten2DList xs (acc ++ x)

	-- or just use concat
	flatten2DList' :: [[a]] -> [a]
	flatten2DList' x = concat x

kraftdorian / binarySearch.js

Created December 17, 2022 19:53

	/**
	* @param {Array<number>} arr Numeric array
	* @param {number} needle Value to search for
	* @return {number} -1 if value was not found, positive value index otherwise
	*/
	function binarySearch(arr, needle) {
	if (!Array.isArray(arr) \|\| needle == null) {
	return -1;
	}

kraftdorian / genElCombObj.ts

Last active August 4, 2022 16:33

Generating Elementary Combinatorial Object

	// Implementation inspired by:
	// https://www.site.uottawa.ca/~lucia/courses/5165-09/GenCombObj.pdf
	// https://docs.microsoft.com/en-us/previous-versions/visualstudio/aa289166(v=vs.70)

	function subsetLexCharacteristicVector(n: number, T: Set<number>): Array<0\|1> {
	const TX: Array<0\|1> = Array.from({ length: n });
	let i = 0;
	for (i; i < n; ++i) {
	TX[i] = T.has(i) ? 1 : 0;
	}

kraftdorian / positionedTree.ts

Created June 28, 2022 12:54

Algorithm to map the input tree so it receives depth and position information, as well as the flat version of its nodes

	interface ITreeNode<Data=unknown> {
	id: string\|null;
	data: Data;
	children: ITreeNode<Data>[];
	}

	interface IPositionedTreeNode<Data=unknown> extends ITreeNode<Data> {
	depth: number;
	parentId: ITreeNode<Data>['id'];
	}

kraftdorian / enumComposition.ts

Last active April 11, 2022 14:08

TypeScript enum composition experiments

	// based on:
	// https://github.com/microsoft/TypeScript/issues/17592#issuecomment-320805415
	// https://www.typescriptlang.org/docs/handbook/enums.html#objects-vs-enums

	enum GlobalEnum {}

	// example enum 1
	enum Example1 {
	A = 'A',
	B = 'B'

kraftdorian / maybe.ts

Last active March 9, 2023 14:50

Maybe typeclass utils in TypeScript

	type Fun<A, B> = (a: A) => B;

	class Just<A> {
	constructor(private readonly _value: A) {}

	valueOf(): A {
	return this._value;
	}
	}

kraftdorian / promiseFunctor.ts

Created November 14, 2021 23:33

TypeScript Promise functor

	function PromiseFunctor<In, Out>(f: (input: In) => Out, value: Promise<In>): Promise<Out> {
	return value.then<Out>(
	a => f(a)
	);
	}

	// ==== TEST ====

	const x = 1;
	const p = Promise.resolve(x);