akitaonrails

def sum(s : Array(Int32), c : Channel(Int32))
  c.send s.reduce(0) { |sum, v| sum + v }
end

def main
  s = [7, 2, 8, -9, 4, 0]
  c = Channel(Int32).new
  spawn {
    sum(s[0..((s.size / 2) - 1)], c)
  }

binarytemple

Inspired by Stuff Goes Bad - Erlang in Anger

Is the global process count indicative of a leak? If so, you may need to investigate unlinked processes, or peek inside supervisors’ children lists to see what may be weird-looking.

defmodule Diags do 

  @doc """

valyala

Optimizing postgresql table for more than 100K inserts per second

• Create UNLOGGED table. This reduces the amount of data written to persistent storage by up to 2x.
• Set WITH (autovacuum_enabled=false) on the table. This saves CPU time and IO bandwidth on useless vacuuming of the table (since we never DELETE or UPDATE the table).
• Insert rows with COPY FROM STDIN. This is the fastest possible approach to insert rows into table.
• Minimize the number of indexes in the table, since they slow down inserts. Usually an index on time timestamp with time zone is enough.
• Add synchronous_commit = off to postgresql.conf.
• Use table inheritance for fast removal of old data:

dcu

#!/usr/bin/env ruby

require 'rest-client'
require 'time'
require 'json'
require 'bundler'

CHECK_GEMS_BEFORE = Time.parse("Feb 8, 2015")

def check_bundler

wesbos

// paste in your console
    speechSynthesis.onvoiceschanged = function() {
      var msg = new SpeechSynthesisUtterance();
      msg.voice = this.getVoices().filter(v => v.name == 'Cellos')[0];
      msg.text = Object.keys(window).join(' ');
      this.speak(msg);
    };

c4milo

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: '', // Does not let Ember inject HTML into the component.
  routing: Ember.inject.service('-routing'),
  breadcrumbs: Ember.computed('routing.currentRouteName', function () {
    let routeName = this.get('routing.currentRouteName');

    let routeNames = routeName.split('.');
    let len = routeNames.length;

c4milo

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: '', // Does not let Ember inject HTML into the component.
  routing: Ember.inject.service('-routing'),
  breadcrumbs: Ember.computed('routing.currentRouteName', function () {
    console.log('--> current route: %s', this.get('routing.currentRouteName'));
    Ember.getOwner(this).lookup('route:' + this.get('routing.currentRouteName')).label;
    this.get('routing.router');
  }),

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

keathley

defprotocol Functor do
  def fmap(data, func)
end

defprotocol Applicative do
  def pure(data)
  def run(wrapped_func, data)
end

defprotocol Monad do

GeoffreyBooth

# RollbackAttributes should also rollback relationships
# Based on http://stackoverflow.com/a/27184207/223225 and https://github.com/emberjs/rfcs/pull/21#issuecomment-135134132

DS.Model.reopen
	rollbackAttributes: ->
		@_super()
		@rollbackRelationships()


	cacheOriginalRelations: ->