morozovamv

import { some, Option, none, getSetoid, option } from 'fp-ts/lib/Option';
import { setoidNumber } from 'fp-ts/lib/Setoid';
import { liftA2 } from 'fp-ts/lib/Apply';

const isEquals = (x: Option<number>, y: Option<number>) => getSetoid(setoidNumber).equals(x, y);

// Monad = Applicative & Chain + Laws

// Laws:
// 1. Left identity: M.chain(M.of(a), f) = f(a)

morozovamv

import { Option, some, none, fromNullable, getSetoid as getSetoidOpt } from 'fp-ts/lib/Option';
import { success, getSetoid as getSetoidRD } from '@devexperts/remote-data-ts';
import { of, Observable, combineLatest } from 'rxjs';
import { setoidNumber, setoidString, getRecordSetoid } from 'fp-ts/lib/Setoid';
import { Function1 } from 'fp-ts/lib/function';

type TUser = {
	name: string;
};

morozovamv

import { Function1 } from 'fp-ts/lib/function';
import { Option, none, some } from 'fp-ts/lib/Option';

// T -> T
const identity = <T>(v: T): T => v;

// (B -> C, A -> B) -> A -> C
const compose = <A, B, C>(f: (Function1<B, C>), g: Function1<A, B>) => (x: A): C => f(g(x));

const plusFive = (n: number): number => n + 5;

morozovamv

import { Option, some, none, option } from "fp-ts/lib/Option";
import { liftA4 } from 'fp-ts/lib/Apply';
import { Function1 } from 'fp-ts/lib/function';

// Task: find the total age of two users

type TPerson = {
    name: string;
    // age: number;
    age: Option<number>;