rkh

# encoding: binary

# Removes any bytes from a string that are not valid UTF-8
class Cleaner
  attr_reader :bytes, :buffer, :outstanding

  def self.clean(str)
    new.tap { |c| c << str }.to_s
  end

jensendarren

class Coffee
  attr_accessor :name
  attr_accessor :strength

  def initialize(name, strength)
    @name = name
    @strength = strength
  end

  def <=>(other_coffee)

madrobby

@media (min--moz-device-pixel-ratio: 1.5),
       (-o-min-device-pixel-ratio: 3/2),
       (-webkit-min-device-pixel-ratio: 1.5),
       (min-device-pixel-ratio: 1.5),
       (min-resolution: 144dpi),
       (min-resolution: 1.5dppx) {

/* Retina rules! */

}

caius

require "uri"

(URI::REGEXP.constants - ["PATTERN"]).each do |rc|
  puts "#{rc}: #{URI::REGEXP.const_get(rc)}"
end

URI::REGEXP::PATTERN.constants.each do |pc|
  puts "#{pc}: #{URI::REGEXP::PATTERN.const_get(pc)}"
end

jeremy

We've seen lots of Ruby feature requests about converting an Enumerable to a Hash: to_h, map_hash, map_to, each_with_hash, etc. Let's look at one common, simple case of this.

Building a key/value mapping from a collection of keys is awkward. We commonly see Hash[*collection.map { |element| [element, calculate(element)] }] or collection.each_with_object({}) { |element, hash| hash[element] = calculate(element) }. Both are verbose. They require boilerplate code that's not relevant to the programmer's intent: to associate an enumerable of keys with calculated values.

Ruby has the idea of an association already: a key and value paired together. It's used by Array#assoc to look up a value from a list of pairs and by Hash#assoc to return a key/value pair. Building up a mapping of key/value pairs is associating keys with values.

So! Consider Enumerable#associate which builds a mapping by associating keys with values:

# Associate filenames with URLs. Before:

schneems

class Add
  attr_reader :result, :is_negative
  def initialize(a, b)
    @result = a + b
    @is_negative = @result < 0
  end
end


def add(a,b)

rkh

# coding: utf-8
require 'sinatra'
set server: 'thin', connections: []

get '/' do
  halt erb(:login) unless params[:user]
  erb :chat, locals: { user: params[:user].gsub(/\W/, '') }
end

get '/stream', provides: 'text/event-stream' do

mewmew

Ten seconds to ponder if a thread is worth it

A userstyle that makes you wait ten seconds before entering a Hacker News thread. I use stylus to manage mine.

.subtext {
  display: inline-block;
 background: linear-gradient(to left, transparent 50%, #f60 50%) right;

rmurphey

What's wrong with Netmag's "Optimize your JavaScript" post

Update: The original post on Netmag has been updated since this was written.

I tweeted earlier that this should be retracted. Generally, these performance-related articles are essentially little more than linkbait -- there are perhaps an infinite number of things you should do to improve a page's performance before worrying about the purported perf hit of multiplication vs. division -- but this post went further than most in this genre: it offered patently inaccurate and misleading advice.

Here are a few examples, assembled by some people who actually know what they're talking about (largely Rick Waldron and Ben Alman, with some help from myself and several others from the place that shall be unnamed).

Things that are just plain wrong

jlong

var parser = document.createElement('a');
parser.href = "http://example.com:3000/pathname/?search=test#hash";

parser.protocol; // => "http:"
parser.hostname; // => "example.com"
parser.port;     // => "3000"
parser.pathname; // => "/pathname/"
parser.search;   // => "?search=test"
parser.hash;     // => "#hash"
parser.host;     // => "example.com:3000"