Interesting Things

• There is a gotcha when creating a Ruby Hash with a default value. If you pass a object to the constructor, such as an empty hash, the same object will be used for all default values. That probably isn’t what you want. Instead, use the form of the constructor which takes a block. Here is an illustration:

  $ irb
  >> trickyhash = Hash.new({})
  => {}
  >> trickyhash[:a][:a] = 1
  => 1
  >> trickyhash[:b]
  => {:a=>1}
  >> betterhash = Hash.new {|h,k| h[k] = {} }
  => {}
  >> betterhash[:a][:a] = 1
  => 1
  >> betterhash[:b]
  => {}
  

• ruby-prof and KCachegrind are very useful for profiling and performance optimization. We had problems compiling the OS X Darwin Port of KCachegrind, though – you may just want to run it on linux.

• Vine Server and Viewer 3.0 has been released.

Ask for Help

• “QuickSilver for Dummies?” – What is a good resource to learn about QuickSilver?