chenglou

let routes = {
  // Regular JS regex over cleaned up URL.
  'book/(\\d+)?/edit': (id) => console.log('handleBookEdit', id),
  'book/(\\d+)?/.+': (_id, _) => console.log('noSuchBookOperation'),
  'book/(\\d+)?': (id) => console.log('getBook', id),

  'shop/(\\d+)?/(\\d+)?': (a, b) => console.log('showSecretShopPage', a, b),
  'shop/index': () => console.log('showShoppingPage'),
  'shop/(.+)': (rest) => console.log('nestedMatch', rest),
  'shop': () => console.log('showShoppingPage'),

chenglou

function pointsOnEllipse1(cx, cy, rx, ry, n) {
  const points = Array(n);

  const step = Math.PI / (n / 2);
  let sin = 0;
  let cos = 1;

  const a = Math.cos(step);
  const b = Math.sin(step);

chenglou

(+) infix operator

Before:

Cn.("one" + "two" + "three")

After:

`one two three`

append

chenglou

// bindings can be isolated/upstreamed. I'm inlining it just for the example
type request;
type response;
[@bs.new] external makeXMLHttpRequest: unit => request = "XMLHttpRequest";
[@bs.send] external addEventListener: (request, string, unit => unit) => unit = "addEventListener";
[@bs.get] external response: request => response = "response";
[@bs.send] external open_: (request, string, string) => unit = "open";
[@bs.send] external send: request => unit = "send";
[@bs.send] external abort: request => unit = "abort";
// =========

chenglou

// This is a proper alternative to
// https://github.com/BuckleScript/bucklescript/blob/b9508105b1a35537bdea9a1fabd10f6c65f776b4/jscomp/bsb/templates/react-hooks/src/FetchedDogPictures/FetchedDogPictures.re#L14
// The one in that file uses Promise, but that's *wrong*.
// We only used promise as a demo of its API. We'll remove it soon.

// As you can see below, the pure XMLHttpRequest code is just as clean,
// less mysterious for all, more performant, extensible, and actually correct.

// Ignore these externals for now. They're just for illustration
// purposes. I just copy pasted the Js code from

chenglou

open Result
open TopTypes
open Infix

let extend = (obj, items) => Json.obj(obj) |?>> current => Json.Object(current @ items)

let log = Log.log

let maybeHash = (h, k) => if Hashtbl.mem(h, k) { Some(Hashtbl.find(h, k)) } else { None }

chenglou

title
Reason 3.2.0

This release is best used in conjunction with upgrading your project to bs-platform 3.1.4.

Rejoice! The release you've all been waiting for. This fixes bring three major quality-of-life improvements when using Reason's formatter, refmt.

Foo

chenglou

reducer: {
  | Edit => (state) => ReasonReact.Update({...state, editText: todo.title})
  | Submit => submitHelper
  | Change(text) => 
    (state) =>
      editing ?
        ReasonReact.Update({...state, editText: text}) :
        ReasonReact.NoUpdate
  | KeyDown(27) =>
    /* escape key */

chenglou

Problem Setup

Assuming JS (this transfers to ReasonReact too): owner renders <Child onClick={this.onClick} />. Child renders <div onClick={this.onClick} />.

Upon div DOM click event:

• Child's onClick is called, sets its state for whatever purpose, then call this.props.onClick (from owner)
• Child re-renders following setState
• Owner's onClick sets owner's own state for whatever purpose
• Owner re-renders following setState
• Owner re-render causes Child to re-render again

chenglou

/* == definition == */

/* two labelled arguments, one unlabelled */
let display = (~message, ~person, time) => 1;
/* with default value */
let display = (~message="hello", ~person="Reason", time) => 1;
/* with type annotation */
let display = (~message: string, ~person: string, time: float) => 1;
/* type annoation and with default */
let display = (~message: string="hello", ~person: string="Reason", time: float) => 1;