kennetpostigo

/* link to playground: https://bit.ly/2uCBISK */
module type Animal = {
  type t = string;
  let make: (string) => t;
  let sprint: (t) => string;
};

module Animal: Animal = {
  type t = string;
  let make = (name) => name;

kennetpostigo

/* link to playground: https://bit.ly/2uP4SgO */
module type Animal = {
  type t;
  let make: (string) => t;
  let sprint: (t) => string;
};

module Animal: Animal = {
  type t = string;
  let make = (name) => name;

kennetpostigo

type binarySearchTree('a) =
  | Empty
  | Node(node('a))
and node('a) = {
  value: 'a,
  left: binarySearchTree('a),
  right: binarySearchTree('a),
};

let compare = (f, s) =>

kennetpostigo

type pets =
| Dog(string)
| Cat(string)
| Hamster(string);

let myPet = Dog("Buddy");

switch (myPet) {
| Dog(name) => "I have a Dog " ++ name ++ "!" 
| Cat(name) => "I have a Cat " ++ name ++ "!" 

kennetpostigo

/* Typical pattern matching with a switch */
switch (expression) {
| pattern1 => expression1
| pattern2 => expression2
| ...
| patternN => expressionN
};

/* Typical destructuring for tuple*/
let (x, y) = tupleOfXY;

kennetpostigo

/* pet is called a type constructor. Dog, Cat, and
   Hamster are called value constructors or tags*/
type pet =
  | Dog
  | Cat
  | Hamster;

/* myPet is of type pet */
let myPet = Dog;

kennetpostigo

type dog = {
  name: string,
  breed: string,
  age: int
};

let myFirstDog = {
  name: "Bubbly",
  breed: "Poodle",
  age: 3

kennetpostigo

let intStringFloat = (1, "one", 1.0);

let tripleStrings = ("Kennet", "Postigo", "@kennetpostigo");

kennetpostigo

/* waddup annotated as a string */
let waddup: string = "waddup fam?!?!";

/* greeting annotated as a function that takes a string and returns string */
let greeting: string => string = name => "Hey " ++ name ++ "!";

/* Type constructor for a function that takes a string and returns unit */
type nonPureGreeting = string => unit;

/* printGreet annotated as nonPureGreeting*/

kennetpostigo

let greet = name => "Hey " ++ name ++ "!"; /* returns string */

let double = x => x * x;

/* Returns unit, signifying it isn't pure and has side-effects */
let printGreet = name => {
  let greeting = greet(name);
  print_string(greeting);
};