From: Phillip Gawlowski <cmdjackryan@...>
Date: 2008-04-29T17:06:55+09:00
Subject: Re: Array#first is not Array#[0]

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Fredrik wrote:
| I made a class that is a subclass of Array :
|
| class MyClass < Array
|   def [](i)
|     "Here you go: #{super(i)}"
|   end
| end
|
| and I thought that Array#first and Array#last was just syntactic sugar
| that would translate to Array#[0] and Array#[-1] respectively. But
| it's not:
|
| irb> g = MyClass.new([1,2,3])
| => [1, 2, 3]
| irb> g[0]
| => "Here you go: 1"
| irb> g.first
| => 1
|
| Now, isn't that really, really crazy? Am I supposed to define
| MyClass#first and MyClass#last separately???

C:\scripts>ruby temp.rb
Here you go: 1
1

C:\scripts>cat temp.rb
class MyClass < Array
~  def [](i)
~    "Here you go: #{super(i)}"
~  end
end

g = MyClass.new([1,2,3])

puts g[0]
puts g.first

C:\scripts>ruby -v
ruby 1.8.6 (2008-03-03 patchlevel 114) [i386-mswin32]

Hm....


- --
Phillip Gawlowski
Twitter: twitter.com/cynicalryan
Blog: http://justarubyist.blogspot.com

~   Calvin: Can you make a living playing silly games?  His Dad:
Actually, you can be among the most overpaid people on the planet.
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