venil7

const a = [
    [1, 2, 3, 4, 5, 6],
    [1, 2, 3, 4, 5, 6],
    [1, 2, 3, 4, 5, 6],
    [1, 2, 3, 4, 5, 6],
    [1, 2, 3, 4, 5, 6],
    [1, 2, 3, 4, 5, 6],
];
enum Dir {
    east, south, west, north

venil7

const sort = (a: number[]): number[] => {
    const split = (a: number[]): [number[], number[]] => {
        const take_left = Math.ceil(a.length / 2);
        const take_right = Math.ceil(a.length / 2);
        const left = a.slice(0, take_left);
        const right = a.slice(take_right);
        return [left, right];

    };
    const merge = (a: number[], b: number[]): number[] => {

venil7

type StateM<S, T> = {
    runState: (state: S) => T,
    then: <U>(func: (t: T, pure: <U>(u: U) => StateM<S, U>) => StateM<S, U>) => StateM<S, U>,
};

const stateM = function <S, T>(runState: (state: S) => [S, T]): StateM<S, T> {
    return {
        runState: function (s: S): T {
            const [, t] = runState(s);
            return t;

venil7

type Maybe<T> = {
    map: <T2>(func: (t: T) => T2) => Maybe<T2>,
    then: <T2>(func: (t: T) => Maybe<T2>) => Maybe<T2>,
    value: (fallback: T) => T
};
const maybe = function <T>(a: T | undefined | null): Maybe<T> {
    const value: [T] | [] = (a !== null && a !== void 0) ? [a] : [];
    return {
        map: function <T2>(func: (t: T) => T2): Maybe<T2> {
            return value.length

venil7

type LastElem<T extends number> = [
    -1,0,1,2,3,4,5
][T];

type A = [number,string, boolean];
type Z = A[LastElem<A['length']>] //boolean

venil7

class Maybe<T> {
    constructor(private val: T | null|undefined) { }
    public get hasVal():boolean {
        return (this.val !== null || this.val !== undefined);
    }
    public value(fallback: T):T {
        return this.hasVal ? this.val : fallback;
    }
    public map<U>(func:(t: T) => U): Maybe<U> {
        return this.hasVal

venil7

import { Subject } from "rxjs";

export const createMiddleware = () => {
  const [action$, state$] = [new Subject(), new Subject()];
  const middleware = store => {
    return dispatch => {
      middleware.run = epic => epic(action$, state$).subscribe(store.dispatch);
      return action => {
        const result = dispatch(action);
        action$.next(action);

venil7

type LGetter<LFrom, LTo> = (f: LFrom) => LTo;
type LSetter<LFrom, LTo> = (t: LTo, f: LFrom) => LFrom;
type LUpdater<T> = ((t: T) => T);
type LModifier<LFrom, LTo> = (u: LUpdater<LTo>) => (f: LFrom) => LFrom;

class Lense<LFrom, LTo> {
    constructor(private get: LGetter<LFrom, LTo>, private set: LSetter<LFrom, LTo>) { }
    public compose<LTo2>(inner: Lense<LTo, LTo2>): Lense<LFrom, LTo2> {
        const _get: LGetter<LFrom, LTo2> = (f: LFrom) => inner.get(this.get(f));
        const _set: LSetter<LFrom, LTo2> = (t2: LTo2, f: LFrom) => this.set(inner.set(t2, this.get(f)), f);

venil7

const useMiddleware = (middlewares, reducer, initState) => {
  const [state, dispatch] = useReducer(reducer, initState);
  const getStore = () => ({ dispatch, getState: () => state });
  const store = applyMiddleware(...middlewares)(getStore)();
  const { dispatch: dispatch_, getState } = store;
  return [getState(), dispatch_];
};

venil7

const useThunk = (reducer, initState) => {
  const [state, dispatch] = useReducer(reducer, initState);
  const thunkDispatch = action => {
    if (typeof action === "function") {
      action(dispatch, () => state);
    } else {
      dispatch(action);
    }
  };
  return [state, thunkDispatch];