From: "David A. Black" <dblack@...>
Date: 2008-05-06T10:33:28+09:00
Subject: Re: Extending Array and assigning to self

Hi --

On Tue, 6 May 2008, yermej wrote:

> On May 5, 6:21 pm, Oliver Saunders <oliver.saund...@gmail.com> wrote:
>> I've got this class that is essentially an array with a few things
>> added. Here's some of it:
>>
>> class Pages
>>
>>    def initialize
>>       @content = []
>>    end
>>
>>    def import(file, page_delimiter = ' ')
>>       @content = file.read.split page_delimiter
>>       self
>>    end
>>
>>    def [](num)
>>       @content[num]
>>    end
>>
>>    def <<(page_content)
>>       @content << page_content
>>    end
>>
>> ...
>>
>> Because I'm basically reimplementing Array I thought it might me more
>> sense to inherit from Array or delegate to Array. The trouble is that I
>> need to assign to @content. How do you suggest I get round this problem?
>> --
>> Posted viahttp://www.ruby-forum.com/.
>
> I would just use Array's own methods. E.g.:
> class Pages < Array
>  def import(file, page_delimiter = ' ')
>    self.clear
>    self.concat file.read.split.page_delimiter

That's actually a space before page_delimiter, not a dot. Or:

   file.read.split(page_delimiter)

just to be sure :-)

>  end
> end
>
> I'm not sure if Array#concat is the best choice here (for some
> definition of best), but it'll work.

In general I'd use #replace rather than #clear plus #concat.


David

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