workshopExamples.re

/* list of strings */
let _ = ["example-1", "example-2", "example-3"]; /* Array of strings */

let _ = [|"example-1", "example-2", "example-3"|]; /* Stating the type of a Reason record */

/* Defining our type */
type basicEvent = {
  location: string,
  years: list(int)
}; 

/* Making a Reason record, Reason knows this is a basicEvent */
{
  location: "Vienna",
  years: [2017, 2018]
}; 

/*** Our first Reason function, already?
 (Use ++ to join strings together) */

let rock = (song) =>
  /* Use {j| ... |j} to interpolate strings */
  Js.log("We're all rocking to " ++ song);

/* Manually specifying types */
let rock = (songName, times) => {
  let timesString = string_of_int(times);
  {j|Rocked out to $(songName) $(timesString) times|j};
};

/* Invoke our function! */
rock("Und er lebte in der großen Stadt", 1);

/* Function with labelled arguments */
let rockLabelled = (~songName, ~times) => {
  let timesString = string_of_int(times);
  {j|Rocked out to $(songName) $(timesString) times|j};
};

/* Invoke our function with labelled arguments! */
rockLabelled(~songName="Und er lebte in der großen Stadt", ~times=1);

/* Making a ReasonReact component with raw function 
MyComponent.make(
  ~foo=bar,
  ~children=[],
  (), /* Making a ReasonReact component with JSX */
  <MyComponent foo=bar />
); 
*/

/* A variant animal type */
type animal =
  | Dog
  | Cat
  | Bird; 

/* Pattern matching our custom animal variant type */
let feed = (pet) =>
  switch pet {
  | Dog => "woof"
  | Cat => "meow"
  | Bird => "chirp"
  };

/*** Destructuring combines code flow and extracts values at the same time,
let's do it here with a list of strings */

let names = ["Daniel", "Jared", "Sean"];

switch names {
| [] => "No names!"
| [personOne] => "One person in list, named " ++ personOne
| [personOne, personTwo] =>
  "Two people in list, both " ++ personOne ++ " and " ++ personTwo
| [personOne, _, personThree, ...rest] =>
  "At least three people in the list, but we picked out " ++ personOne ++ " and " ++ personThree
}; /* Destructuring a record type */

let event = {location: "Vienna", years: [2017, 2018]};

let message =
  switch event {
  | {location: "Vienna", years} =>
    "This event was in Vienna for " ++ string_of_int(List.length(years)) ++ " years"
  | {location, years: [2018, 2019]} =>
    "This event was in " ++ location ++ " for 2018 and 2019"
  | event => "This is a generic event"
  }

/* From https://github.com/reasonml-community/bs-moment/blob/master/src/MomentRe.re */; 

/* Binding to JavaScript libraries */

[@bs.val] external alert : string => unit = "alert";

[@bs.val] external imul : (int, int) => int = "Math.imul";

[@bs.send] external reverse : array('someKind) => array('someKind) = "";

let identity: ('a, 'a) => 'a = [%bs.raw
  {|
    function(x,y) {
      /* Dangerous JavaScript! */
      /* You're on your own here, the compiler will trust you! */
      return x < y
      }
  |}
];

/* alert("Bound successfully!"); */

imul(1, 2);

reverse([|1, 2, 3|]);

identity(1, 2);

Shouldn't the variable name here be songName instead of song?

yes, you're right