staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

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.

---

JulienPalard

#!/usr/bin/env python


def curry(func):
    """
    Decorator to curry a function, typical usage:

    >>> @curry
    ... def foo(a, b, c):
    ...    return a + b + c

c4milo

Digesting VMDK spec

Particularly, virtual disks types are very confusing. This document is an attempt to disentangle that and make easier the design of an implementation.

Flat or preallocated disk

• Monolithic or one-file: Single flat extent with separate descriptor file. createType: monolithicFlat
• Split or multiple files: 2gb preallocated extents or smaller, to account for file system limits. createType: 2GbMaxExtentFlat
• VMFS (managed):
  • Zeroed: Thick (flat) disk on VMFS, with blocks zeroed on first use. createType: vmfsPreallocated

sunaot

module Ruby
  module Spock
    def spec(description, definition = nil, &proc_definition)
      raise ArgumentError if [ definition, proc_definition ].all? {|d| d.nil? }
      if definition.nil?
        spec_runner(description, proc_definition)
      else
        spec_runner(description, definition)
      end
    end

myronmarston

I highly suspect that the RSpec core team all use black backgrounds in their terminals because sometimes the colors aren’t so nice on my white terminal

I certainly use a black background. I'm not sure about the other RSpec core folks. Regardless, if there are some color changes we can make that would make output look good on a larger variety of backgrounds, we'll certainly consider that (do you have some suggested changes?). In the meantime, the colors are configurable, so you can change the colors to fit your preferences on your machine. First, create a file at

bodiam

* {
    font-size: 12pt;
    font-family: monospace;
    font-weight: normal;
    font-style: normal;
    text-decoration: none;
    color: black;
    cursor: default;
}

julianlam

Provisioning and usage of unprivileged LXC containers via indirect login or script

As I've discovered, managing LXC containers is fairly straightforward, but when building out a system for provisioning out user maintained instances of NodeBB, it was imperative that unprivileged LXC containers were used, so that in the event of shell breakout from NodeBB followed by privilege escalation of the saas user, the root user in the LXC container would only be an unprivileged user on the host machine.

During the course of development, I ran into numerous blockers when it came to managing LXC containers in unexpected circumstances. Namely:

• Using LXC in a subshell is not directly supported. This usually happens under one of the following two circumstances:
  • After switching users via su or executing lxc-* commands as another user via sudo
  • Executing lxc-* commands via a program, application, or script. In my case, a Node.js application.

tenderlove

l={};s=m=[];i=pc=mc=0
alias p proc
h={'>':p{mc+=1},'<':p{mc-=1},'+':p{m[mc]+=1},'-':p{m[mc]-=1},'.':p{putc m[mc]}}
j={'[':->(i){s<<i;->(){pc=l[pc-1]+1 if m[mc]==0}},']':->(i){o=s.pop;l[o]=i;p{pc=o}}}
ins=DATA.each_char.map{|c|c=:"#{c}";x=(j[c]||->(_){h[c]||p{}}).(i);i+=1;x}
while k=ins[pc];pc+=1;m[mc]||=0;k.();end

__END__
[ This program prints "Hello World!" and a newline to the screen, its
  length is 106 active command characters. [It is not the shortest.]

paulirish

What forces layout / reflow

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.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

benjchristensen

Response to https://twitter.com/jeffreymaxwell/status/705760483391963136 requiring more than the 77 characters left on Twitter.

DISCLAIMER: The quality of writing and thinking here is aligned with a Twitter conversation, not a blog post, presentation, or book ;-)

Synchronous RESTful communication between Microservices is an anti-pattern ... you seem to being saying that the Netflix architecture (hystrix, eureka, ribbon, ..) is broken ... hmm what would @benjchristensen say?