| import React from 'react'; | |
| import Coroutine from 'react-coroutine'; | |
| import Deferred from './Deferred.js'; | |
| export default Coroutine.create(Counter); | |
| async function* Counter() { | |
| let counter = 0; | |
| while (true) { | |
| let event = new Deferred(); |
NOTE: The Tree-sitter API and documentation has changed and improved since this guide was created. I can't guarantee this is up to date.
Tree-sitter is the new way Atom is providing language recognition features, such as syntax highlighting, code folding, autocomplete, and more. In contrast to TextMate grammars, which work by regex matching, Tree-sitter will generate an entire syntax tree. But more on that can be found in it's own docs.
Here, we look at making one from scratch.
| // This code now lives at https://github.com/samthor/undoer (or 'undoer' on NPM). |
export x = 42
This SQL creates a Postgres function to generate sequential, numeric, unique IDs in a consistent format across services. Useful for database sharding or microservices.
Draws heavily on Instagram's ID generator, via Rob Conery, with minor modifications.
The main changes are that the unique number resolution is per-second rather than per-millisecond. This is to reduce key size below 2^53^-1 so that generated IDs that are under Javascripts Number.MAX_SAFE_INTEGER limit . This is important if you're using these on a Node.js server (e.g. our use case is an Express API using Hashids).
Max IDs are in the order of 51 bits, broken down as follows:
[02:06 PM] acemarke: @Steven : a couple other thoughts on the whole NODE_ENV thing. First, per my comments, it really is a Node concept. It's a system environment variable that Node exposes to your application, and apparently the Express web server library popularized using its value to determine whether to do optimizations or not
[02:08 PM] acemarke: Second, because of its use within the Node ecosystem, web-focused libraries also started using it to determine whether to they were being run in a "development" environment vs a "production" environment, with corresponding optimizations. For example, React uses that as the equivalent of a C #ifdef to act as conditional checking for debug logging and perf tracking. If process.env.NODE_ENV is set to "production", all those if clauses will evaluate to false.
Third, in conjunction with a tool like UglifyJS that does minification and removal of dead code blocks, a clause that is surrounded with if(process.env.NODE_ENV !== "development")
Doing require extensions correctly is essential, because:
nyc need it to reliably supply coverage information that takes into account sourcemaps from upstream transforms.
All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.
Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.
elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
All lower case JSX tags will now be treated as HTML/SVG elements. They will no longer be treated as custom components in scope.
The React element produced by JSX can be either a React class that exists in the local scope or a global scope HTML/SVG element depending on a convention.
Previous Behavior
Currently, when you use React JSX to define a HTML element you can use any known HTML tag. E.g:
| (ns react-cljs.core | |
| (:require-macros [reactjs.macros :refer [pure]]) | |
| (:require React [reactjs.core :as r])) | |
| (enable-console-print!) | |
| (declare render-ui) | |
| (defn render-counter [id state cb] | |
| (pure state |