From: "David A. Black" <dblack@...>
Date: 2007-10-09T19:26:58+09:00
Subject: Re: Indexers and blocks?

Hi --

On Tue, 9 Oct 2007, Stephan Mueller wrote:

> Hi,
>
> if I have an array-like class, is it possible to call the index with a
> block?
>
> class MyClass
>  def find(key)
>    return nil
>  end
>
>  def [](key)
>    if (val = find(key))
>      return val
>    else
>      return yield(key) if block_given?
>    end
>  end
> end
>
> c = MyClass.new
> c[:test] { "default" }
>
> triggers a syntax error (Ruby 1.8.6).
>
> Is there a way to accomplish this or do i need to do tricks like giving
> the block to the constructor?

You can do:

   c.[](:text) { "default" }

but that's kind of ugly. I guess the whole point of c[] is to conceal
the fact that it's a method call, which means that it then doesn't try
to duplicate the full method call anatomy.


David

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