kp666

Supercompilation is a deep program transformation technique due to V. F. Turchin, a prominent computer scientist, cybernetician, physicist, and Soviet dissident. He described the concept as follows [^supercompiler-concept]:

A supercompiler is a program transformer of a certain type. The usual way of thinking about program transformation is in terms of some set of rules which preserve the functional meaning of the program, and a step-by-step application of these rules to the initial program. ... The concept of a supercompiler is a product of cybernetic thinking. A program is seen as a machine. To make sense of it, one must observe its operation. So a supercompiler does not transform the program by steps; it controls and observes (SUPERvises) the running of the machine that is represented by the program; let us call this machine M₁. In observing the operation of

kp666

var translate = (function () {
    var symbols = {
        a: '([]+![])[+!+[]]',
        b: '([]+{})[+!+[]+!+[]]',
        c: '([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]]',
        d: '([]+[][+[]])[+!+[]+!+[]]',
        e: '([]+[][+[]])[+!+[]+!+[]+!+[]]',
        f: '([]+[][+[]])[+!+[]+!+[]+!+[]+!+[]]',
        g: '([]+([]+[])[([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]]+([]+{})[+!+[]]+([]+[][+!+[]])[+!+[]]+([]+![])[+!+[]+!+[]+!+[]]+([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+([]+!![])[+!+[]]+([]+!![])[+!+[]+!+[]]+([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]]+([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+([]+{})[+!+[]]+([]+!![])[+!+[]]])[+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]', 
        h: '(+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[])[([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+([]+{})[+!+[]]+([]+([]+[])[([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]]+([]+{})[+!+[]]+([]+[][+!+[]])[+!+[]]+([]+![])[+!+[]+!+[]+!+[]]+([]+{})[+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+([]+!![])[+!+[]]+([]+!![])[+!+[]+!+[]]

kp666

# lib/tasks/db.rake
namespace :db do

  desc "Dumps the database to db/APP_NAME.dump"
  task :dump => :environment do
    cmd = nil
    with_config do |app, host, db, user|
      cmd = "pg_dump --host #{host} --username #{user} --verbose --clean --no-owner --no-acl --format=c #{db} > #{Rails.root}/db/#{app}.dump"
    end
    puts cmd

kp666

Types of index scans

Indexes

Sequential Scan:

• Read every row in the table
• No reading of index. Reading from indexes is also expensive.

kp666

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

So you're curious in learning this new thing called Reactive Programming, particularly its variant comprising of Rx, Bacon.js, RAC, and others.

Learning it is hard, even harder by the lack of good material. When I started, I tried looking for tutorials. I found only a handful of practical guides, but they just scratched the surface and never tackled the challenge of building the whole architecture around it. Library documentations often don't help when you're trying to understand some function. I mean, honestly, look at this:

Rx.Observable.prototype.flatMapLatest(selector, [thisArg])

Projects each element of an observable sequence into a new sequence of observable sequences by incorporating the element's index and then transforms an observable sequence of observable sequences into an observable sequence producing values only from the most recent observable sequence.