├── README.md
├── errors.js
├── logo.png
├── no-any.js
├── nominal-types.js
├── operators.js
├── parametric-polymorphism.js
├── related-types.js
└── type-refinement.js


/README.md:
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 1 | # Hegel Literature and Demos
 2 | <img src="./logo.png" width="150"> 
 3 | 
 4 | 
 5 | 
 6 | | Тема                          | Ссылки                                                            |
 7 | | ----------------------------- | ----------------------------------------------------------------- |
 8 | | There is a bluebird in my talk that wants to get out    | https://www.youtube.com/watch?v=NCf5nthB1tA   |
 9 | | AST в JavaScript              | https://www.youtube.com/watch?v=ILSpvViUlPU                       |
10 | | Системы типов в двух словах   | https://www.youtube.com/watch?v=nFtO6419A5k                       |
11 | | Б.Пирс Типы в ЯП              | https://www.ozon.ru/context/detail/id/7410082                     |
12 | | TDD with Idris                | https://www.manning.com/books/type-driven-development-with-idris  |
13 | | Структура и Интерпретация Компьютерных Программ     | https://www.ozon.ru/context/detail/id/5322055   |
14 | | Dragon Book                   | https://www.ozon.ru/context/detail/id/3829076                     |
15 | | Sea of Nodes                  | https://darksi.de/d.sea-of-nodes                                  |
16 | | Variances                     | https://habr.com/ru/post/218753/                                  |
17 | | Don't use cast                     | https://gustedt.wordpress.com/2014/04/02/dont-use-casts-i/   |
18 | | Лекции по выводу типов в GHC 8.8   | https://www.youtube.com/watch?v=_HYI7zjkrEs                  |
19 | 


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/errors.js:
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 1 | type User = {
 2 |   id: number,
 3 |   email: string
 4 | };
 5 | 
 6 | const NOT_FOUND = { status: 404, message: "User not found" };
 7 | 
 8 | function getByEmail(email: string): User {
 9 |   if (Math.random() > 0.5) {
10 |     return { id: 1, email };
11 |   }
12 |   throw new Error("User is not presented in DB");
13 | }
14 | 
15 | function signIn(email: string) {
16 |   if (false) {
17 |     throw 2;
18 |   }
19 |   return getByEmail(email);
20 | }
21 | 
22 | function signInRoute(email) {
23 |   try {
24 |     return signIn(email);
25 |   } catch (e) {
26 |     if (e instanceof Error) {
27 |       throw NOT_FOUND;
28 |     }
29 |     throw e;
30 |   }
31 | }
32 | 


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/logo.png:
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https://raw.githubusercontent.com/JSMonk/hegel-literature/a8a09f335e366d504efdb8655391e120ac5ea4f9/logo.png


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/no-any.js:
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1 | function toString(obj: any): string {
2 |   return `[${obj}]`;
3 | }


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/nominal-types.js:
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 1 | class Animal {}
 2 | 
 3 | class Dog extends Animal {
 4 |   woof() {}
 5 | }
 6 | 
 7 | class Cat extends Animal {
 8 |   meow() {}
 9 | }
10 | 
11 | const cats: Array<Cat> = [new Cat()];
12 | const animals: Array<Animal> = cats;
13 | 
14 | animals[1] = new Dog();
15 | 


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/operators.js:
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 1 | type User = { id: number };
 2 | const user: ?User= { id: 0 };
 3 | 
 4 | if (user) {}
 5 | 
 6 | for (let i = 10; i--; ) {}
 7 | 
 8 | while(user) {}
 9 | 
10 | if ("b" in 2) {}
11 | 
12 | if (typeof user === "void") {}


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/parametric-polymorphism.js:
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1 | function id(x) {
2 |   return x;
3 | }
4 | 
5 | const num = id(2);
6 | const str = id("str");
7 | const fn = id(id);
8 | 


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/related-types.js:
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 1 | class User {}
 2 | class Chat {}
 3 | class Message {}
 4 | 
 5 | const models = { User, Chat, Message };
 6 | 
 7 | type Models = $TypeOf<models>;
 8 | 
 9 | function model<T: $Keys<Models>>(modelName: T): $PropertyType<Models, T> {
10 |   return models[modelName];
11 | }
12 | 
13 | // -------------------------------------------------------------------------
14 | 
15 | const UserModel = model("User");
16 | 
17 | const user: User = new UserModel();


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/type-refinement.js:
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 1 | const variable1: number | Array<number> = 2;
 2 | const variable2: { a: { b: number }, c: string } | { a: { b: string }, d: ?boolean } = { a: { b: "str" } };
 3 | 
 4 | if (typeof variable1 === "number") {
 5 |   const res = variable1;
 6 | } else {
 7 |   const res = variable1;
 8 | }
 9 | 
10 | 
11 | if (typeof variable2.a.b === "number") {
12 |   const res = variable2.c;
13 | }
14 | 
15 | if ("c" in variable2) {
16 |   const res = variable2;
17 | } else {
18 |   const res = variable2;
19 | }
20 | 
21 | if (variable1 instanceof Array) {
22 |   const res = variable1;
23 | }


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