From: "Michael T. Richter" <ttmrichter@...>
Date: 2008-07-10T20:07:53+09:00
Subject: Re: Overloading the []-Operator

--=-1okUUBMjCV5nLoc5w3zR
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

On Thu, 2008-07-10 at 19:55 +0900, Matthias Winkelmann wrote:

> Hi,
> 
> I'm trying to overload the [ ] operator. It works fine for read-only
> access:
> 
> def [](acc)
>  @myValues[acc]
> end
> 
> However, I'd also need write access. I've tried:
> 
> def [](acc)=(value)
>    @myValues[acc] = value
>   end
> 
> And get a syntax error on the first line. I'd appreciate any help.
> 
> Matt


irb(main):017:0> class Junk
irb(main):018:1> def initialize ; @myValues = {} ; end
irb(main):019:1> def [] (acc) ; @myValues[acc] ; end
irb(main):020:1> def []= (acc,value) ; @myValues[acc] = value ; end
irb(main):021:1> end
=> nil
irb(main):022:0> a = Junk.new
=> #<Junk:0xb7baa538 @myValues={}>
irb(main):023:0> a[5]
=> nil
irb(main):024:0> a[5]=5
=> 5
irb(main):025:0> a[5]
=> 5
irb(main):026:0> 

-- 
Michael T. Richter <ttmrichter@gmail.com> (GoogleTalk:
ttmrichter@gmail.com)
I'm not schooled in the science of human factors, but I suspect surprise
is not an element of a robust user interface. (Chip Rosenthal)

--=-1okUUBMjCV5nLoc5w3zR--