Re: WTF is Struct? Oh! [was Re: Ruby beginner question 2]

On Aug 22, 2005, at 2:37 PM, Gavin Kistner wrote:
> On Aug 22, 2005, at 2:31 AM, Robert Klemme wrote:
>> A simpler alternative is to just use Struct:
>>
>> # direct
>> Song = Struct.new :name, :artist, :duration
>>
>> class Song
>>   # other methods
>> end
>
> Wait wait wait...I never grokked Struct before.
>
> Is it really just a convenient factory for generating classes with  
> a set of accessor properties, and a constructor that accepts zero  
> or more of those properties in order?

yup. though don't be caught by this:

irb(main):003:0> B=Struct.new :g
=> B
irb(main):004:0> class B; def blah; p @g; end; end
=> nil
irb(main):005:0> B.new(5).blah
nil
=> nil

i frequently write quick Struct's and later refactor them into real  
classes.

Alex