staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

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This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

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cloudRoutine

open System.Collections.Generic
open Microsoft.FSharp.Collections


[<RequireQualifiedAccess>]
module Folds =

    // These are the fast implementations we actually want to use

gtallen1187

"Scar Tissues Make Relationships Wear Out"

04/26/2103. From a lecture by Professor John Ousterhout at Stanford, class CS142.

This is my most touchy-feely thought for the weekend. Here’s the basic idea: It’s really hard to build relationships that last for a long time. If you haven’t discovered this, you will discover this sooner or later. And it's hard both for personal relationships and for business relationships. And to me, it's pretty amazing that two people can stay married for 25 years without killing each other.

[Laughter]

> But honestly, most professional relationships don't last anywhere near that long. The best bands always seem to break up after 2 or 3 years. And business partnerships fall apart, and there's all these problems in these relationships that just don't last. So, why is that? Well, in my view, it’s relationships don't fail because there some single catastrophic event to destroy them, although often there is a single catastrophic event around the the end of the relation

MichalZalecki

// Import all

import Rx from "rxjs/Rx";

Rx.Observable
  .interval(200)
  .take(9)
  .map(x => x + "!!!")
  .bufferCount(2)
  .subscribe(::console.log);

mavnn

module Logary.Obnoxious

open Logary
open Logary.Configuration
open Logary.Targets
open Hopac
open Hopac.Infixes
open Hopac.Job.Global
open Hopac.Extensions.Async
open Hopac.Extensions.Async.Global

eulerfx

/// Operations on Berkley sockets.
[<CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
module Socket =

  /// Executes an async socket operation.
  let exec (alloc:unit -> SocketAsyncEventArgs, free:SocketAsyncEventArgs -> unit) (config:SocketAsyncEventArgs -> unit) (op:SocketAsyncEventArgs -> bool) (map:SocketAsyncEventArgs -> 'a) =
    Async.FromContinuations <| fun (ok, error, _) ->

      let args = alloc ()

thinkbeforecoding

open Hopac
open Hopac.Infixes
open NodaTime
open Logary
open Logary.Metrics.Reservoirs
open Logary.Configuration
open Logary.Targets
open Metric

module PointName =

acdlite

// getComponent is a function that returns a promise for a component
// It will not be called until the first mount
function asyncComponent(getComponent) {
  return class AsyncComponent extends React.Component {
    static Component = null;
    state = { Component: AsyncComponent.Component };

    componentWillMount() {
      if (!this.state.Component) {
        getComponent().then(Component => {

mrange

module RuleIt =

  type Navigator          = Navigator         of (unit -> unit)
  type UserIdentity       = UserIdentity      of uint64
  type ResourceIdentity   = ResourceIdentity  of uint64
  type UserAction         =
    | Create  of ResourceIdentity
    | Read    of ResourceIdentity
    | Update  of ResourceIdentity
    | Delete  of ResourceIdentity

mrange

On the topic of data locality and performance

Full source code can be found here

It is well-known that a hard disk has a long delay from that we request the data to that we get the data. Usually we measure the hard disk latency in milliseconds which is an eternity for a CPU. The bandwidth of a hard disk is decent good as SSD:s today can reach 1 GiB/second.

What is less known is that RAM has the same characteristics, bad latency with good bandwidth.

You can measure RAM latency and badndwidth using Intel® Memory Latency Checker. On my machine the RAM latency under semi-high load is ~120 ns (The 3r:1w bandwidth is 16GiB/second). This means that the CPU on my machine has to wait for ~400 cycles for data, an eternity.