olih

Processing JSON using jq

jq is useful to slice, filter, map and transform structured json data.

Installing jq

On Mac OS

brew install jq

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

dannguyen

Credit to these very helpful Internet sources:

• r/OutOfTheLoop: Where did the "༼ つ ◕_◕ ༽つ" emoticon get started?
• tldp: Bash Prompt HOWTO: ANSI Escape Sequences
• StackOverflow: A.D.'s answer to Custom Bash prompt is overwriting itself

The StackOverflow discussion, in particular, got me over the problem of the cursor position being screwed up (overlapping and overwriting the line) when doing escape sequences. Apparently you have to prepend \[ and append \] around each escape sequence.

Avaq

const I  = x => x
const K  = x => y => x
const A  = f => x => f (x)
const T  = x => f => f (x)
const W  = f => x => f (x) (x)
const C  = f => y => x => f (x) (y)
const B  = f => g => x => f (g (x))
const S  = f => g => x => f (x) (g (x))
const S_ = f => g => x => f (g (x)) (x)
const S2 = f => g => h => x => f (g (x)) (h (x))

carcinocron

// Run this in the F12 javascript console in chrome
// if a redirect happens, the page will pause
// this helps because chrome's network tab's
// "preserve log" seems to technically preserve the log
// but you can't actually LOOK at it...
// also the "replay xhr" feature does not work after reload
// even if you "preserve log".

window.addEventListener("beforeunload", function() { debugger; }, false)

Integralist

const flattenTco = ([first, ...rest], accumulator) => 
  (first === undefined)
    ? accumulator
    : (Array.isArray(first))
      ? flattenTco([...first, ...rest])
      : flattenTco(rest, accumulator.concat(first))
  
const flatten = (n) => flattenTco(n, []);
  
console.log(flatten([[1,[2,[[3]]]],4,[5,[[[6]]]]]))

Integralist

• defprotocol: defines an interface
• deftype: create a bare-bones object which implements a protocol
• defrecord: creates an immutable persistent map which implements a protocol

Typically you'll use defrecord (or even a basic map);
unless you need some specific Java inter-op,
where by you'll want to use deftype instead.

Note: defprotocol allows you to add new abstractions in a clean way Rather than (like OOP) having polymorphism on the class itself,

jsturgis

var mediaJSON = { "categories" : [ { "name" : "Movies",
        "videos" : [ 
		    { "description" : "Big Buck Bunny tells the story of a giant rabbit with a heart bigger than himself. When one sunny day three rodents rudely harass him, something snaps... and the rabbit ain't no bunny anymore! In the typical cartoon tradition he prepares the nasty rodents a comical revenge.\n\nLicensed under the Creative Commons Attribution license\nhttp://www.bigbuckbunny.org",
              "sources" : [ "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4" ],
              "subtitle" : "By Blender Foundation",
              "thumb" : "images/BigBuckBunny.jpg",
              "title" : "Big Buck Bunny"
            },
            { "description" : "The first Blender Open Movie from 2006",
              "sources" : [ "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/ElephantsDream.mp4" ],

eliasah

##########################################################################################
# use case: training a classifier
# 
# Many systems classify documents by assigning “tag” or “category” fields. Classifying
# documents can be a tedious manual process and so in this example we will train a classifier
# to automatically spot keywords in new documents that suggest a suitable category.

curl -XGET "http://localhost:9200/products_fr/_search" -d'
{
  "query": {

john2x

Clojure Destructuring Tutorial and Cheat Sheet

(Related blog post)

Simply put, destructuring in Clojure is a way extract values from a datastructure and bind them to symbols, without having to explicitly traverse the datstructure. It allows for elegant and concise Clojure code.

Vectors and Sequences