bmwill

OUTDATED

Futures 0.3 and Async/Await

This document will try to give a short tutorial of how to use the new style futures (0.3), how to use Async/Await, and how to use the compatibility layer to interoperate with old futures (0.1) and tokio.

Terminology

When dealing with futures in this new world there are a lot of different parts and it can be difficult to keep things straight at times. As such here is a quick run down of the different parts and what they are.

Matthias247

Async/Await - The challenges besides syntax - Cancellation

This is the second article in a series of articles around Rusts new async/await feature. The first article about interfaces can be found here.

In this part of the series we want to a look at a mechanism which behaves very different in Rust than in all other languages which feature async/await support. This mechanism is Cancellation.

HenningTimm

Memory profiling Rust code with heaptrack in 2019

I recently ran into a classic case of "our code is using way more memory than it should". So I took my first dive into memory profiling Rust code. I read several posts about this, including the following

• KodrAus' gist on profiling rust
• This reddit thread
• Brendan D. Gregg's post about memory flamegraphs
• Bradlee Speice's A Case Study in Heaptrack

rfikki

admin.addPeer("enode://bfb8f20e0bda834faecdca1a01de66b9a7fc184c2a30fca681e6e018aaae91db5d80021f9bf9b5ab598c06264b97a7e1dac1068d16267573c033245b62a2f1f7@47.103.147.67:30303");
admin.addPeer("enode://4d0f2ee1d123159525e4a98fb698076469099d326fe60499ec886e3864fbcc71d3f7b9003fa122058883d6924444bebcfc6bb18b6eb7010cc11571e9ab8ea45b@51.158.104.10:30303");
admin.addPeer("enode://40c212f40b6912dffe848e5c97987e527a3f6da8305a05de2d59cf9444a2d5e183bbb18fab95a7b7e5dc8fa7c30dad0f30f22d39bcdf22c97a1c5ae1fc0f2986@54.175.52.44:30303");
admin.addPeer("enode://26800845069faba9791520112350d0a5f0cd52d0af890196beeb5195345e17b00e60e27f260f6e24087e6066c2637e210f389a9795360b1251c17e58b95446f9@85.25.137.11:30303");
admin.addPeer("enode://2daaae5f69037e575fe169d64aa668223effdf60c2a1898492bf0a9bd45d4991355431ec5bcf9cba2eed1d750cd425d689e0e5cc7141f2954623e3d233ad44ed@80.221.111.50:30303");
admin.addPeer("enode://7a3041767f5bb2f96edf824b186ddb97fdff074675dd55f71347da3b7586210a6e09507415291d2c952dd34184b33562f9a4ecb0188ce3781df644e69901f660

kestein

Under the dependencies section, put

<crate name>={git="ssh://git@github.com/<organization>/<reponame>.git"}

It is pretty similar to a github repo's ssh cloning link, however the : is replaced with a / and ssh:// is prepended to the URL.

git@github.com:my-organization/my-repo.git vs ssh://git@github.com/my-organization/my-repo.git

The SSH URL needs to be used because Cargo is currently unable to handle the authentication prompt that comes up when an HTTPS link is used.
Make sure that the matches the crate name in the target repo's Cargo.toml. The repo name will not override what is in the Cargo.toml if it is a different value.

lattner

Swift Concurrency Manifesto

Author: Chris Lattner

Chinese Translation by Jason Yu

Contents

• Introduction
• Overall Vision

henrik

defmodule RegexCase do
  defmacro regex_case(string, do: lines) do
    new_lines = Enum.map lines, fn ({:->, context, [[regex], result]}) ->
      condition = quote do: String.match?(unquote(string), unquote(regex))
      {:->, context, [[condition], result]}
    end

    # Base case if nothing matches; "cond" complains otherwise.
    base_case = quote do: (true -> nil)
    new_lines = new_lines ++ base_case

CMCDragonkai

Rust/Haskell: Higher-Kinded Types (HKT)

A higher kinded type is a concept that reifies a type constructor as an actual type.

A type constructor can be thought of in these analogies:

• like a function in the type universe
• as a type with a "hole" in it

pixeltrix

When should you use DateTime and when should you use Time?

It's a common misconception that [William Shakespeare][1] and [Miguel de Cervantes][2] died on the same day in history - so much so that UNESCO named April 23 as [World Book Day because of this fact][3]. However because England hadn't yet adopted [Gregorian Calendar Reform][4] (and wouldn't until [1752][5]) their deaths are actually 10 days apart. Since Ruby's Time class implements a [proleptic Gregorian calendar][6] and has no concept of calendar reform then there's no way to express this. This is where DateTime steps in:

>> shakespeare = DateTime.iso8601('1616-04-23', Date::ENGLAND)
=> Tue, 23 Apr 1616 00:00:00 +0000
>> cervantes = DateTime.iso8601('1616-04-23', Date::ITALY)
=> Sat, 23 Apr 1616 00:00:00 +0000

wincent

2015-01-29 Unofficial Relay FAQ

Compilation of questions and answers about Relay from React.js Conf.

Disclaimer: I work on Relay at Facebook. Relay is a complex system on which we're iterating aggressively. I'll do my best here to provide accurate, useful answers, but the details are subject to change. I may also be wrong. Feedback and additional questions are welcome.

What is Relay?

Relay is a new framework from Facebook that provides data-fetching functionality for React applications. It was announced at React.js Conf (January 2015).