peter

Programming Languages

Lisp (1958)

Interpreted, dynamic typing, functional

C (1972)

Compiled, static typing, imperative (procedural)

peter

// 1. Swith two variables

// ES5
var temp = a;
a = b;
b = temp;

// ES6 - destructuring assignment
[b, a] = [a, b];

peter

// BEFORE REFACTORING (IMPERATIVE)
var filteredLinks = [];
var weekdayCounts = {};
// Limit to 4 links per weekday.
// Loop through all links and keep track of
// how many are in each weekday.
widget.links.forEach(function(link) {
  var weekday = link.group;
  if (weekdayCounts[weekday] === undefined) {
    weekdayCounts[weekday] = 0;

peter

'use strict';

var R = require('ramda');

var blank = function(value) {
  return value == null || (typeof value === 'string' && value.trim().length === 0);
};

var present = function(value) {
  return !blank(value);

peter

class Foo
  def bar
  end
end

peter

namespace :db do
  # NOTE: In Rails 3 there will be a db:setup task but it only works if ActiveRecord::Base.schema_format == :ruby
  # See http://afreshcup.com/2009/05/11/seed-data-in-rails-3
  # The following patch fixes db:schema:load to work with schema_format :sql:
  # https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/2789-make-rake-task-dbschemaload-compatible-with-sql-schema-format
  desc 'Recreate the database, load the schema, and initialize with the seed data'
  task :super_setup => [ 'db:drop', 'db:create' ] do
    system("cat db/development_structure.sql db/development_data.sql | script/dbconsole")
    seed_file = File.join(Rails.root, 'db', 'seeds.rb')
    load(seed_file) if File.exist?(seed_file)      

peter

'use strict';

// NOTE: this in memory locking approach will only work with a single process
// You might use something like Redis och memcachached for storing the lock if you need to lock
// across several processes.
var synchronizedFunction = function(lockIdFn, fn) {
  var locks = {};
  var synchronized = function() {
    var args = Array.prototype.slice.call(arguments),
        lockId = lockIdFn.apply(null, args);

peter

# In lib/tasks/deploy.rake
namespace :deploy do
  def write_error_page(status, locale = nil)
    dest_filename = [status.to_s, locale, "html"].compact.join(".")
    File.open(File.join(Rails.root, "public", dest_filename), "w") do |file|
      path = File.join(Rails.root, "app", "views", "errors", "#{status}.rhtml")
      file.print ERB.new(File.read(path)).result
    end   
  end

peter

describe "Mocking/Stubbing Associations with RSpec" do
  it "can be done with proxy_target" do
    # Suppose the Article model has an after_save callback that invokes notify_change on the author
    # if the article has been changed.
    @article.author.proxy_target.should_receive(:notify_change)
    @article.update_attributes(:body => "new body")
  end
end

peter

class Author
  def invoke_inside(method, *args)
    self.send(method, *args)
  end
end

author = Article.first.author
def author.foobar
  "foobar"
end