jasonLaster

Time Travel Debugging

Time Travel refers to the ability to record a tab and later replay it ([WebReplay][wrr]). The technology is useful for local development, where you might want to:

• pause and step forwards or backwards
• pause and rewind to a prior state
• rewind to the time a console message was logged
• rewind to the time an element had a certain style or layout
• rewind to the time a network asset loaded

nikic

Why objects (usually) use less memory than arrays in PHP

This is just a small post in response to [this tweet][tweet] by Julien Pauli (who by the way is the release manager for PHP 5.5). In the tweet he claims that objects use more memory than arrays in PHP. Even though it can be like that, it's not true in most cases. (Note: This only applies to PHP 5.4 or newer.)

The reason why it's easy to assume that objects are larger than arrays is because objects can be seen as an array of properties and a bit of additional information (like the class it belongs to). And as array + additional info > array it obviously follows that objects are larger. The thing is that in most cases PHP can optimize the array part of it away. So how does that work?

The key here is that objects usually have a predefined set of keys, whereas arrays don't:

etorreborre

trait Car {
  val doorsNb: Int

  override def equals(a: Any) = {
    a match {
      case c: Car => doorsNb == c.doorsNb
      case other  => false 
    }
  }
}

MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname