From: Ralf Mueller <ralf.mueller@...>
Date: 2009-08-24T17:06:08+09:00
Subject: Re: Stupid OpenStruct question

Robert Klemme wrote:
> On 24.08.2009 06:02, Terry Smith wrote:
>> got it
>>
>> ff = s.fields
>>
>> ff.each{|g|
>>   puts s.instance_eval g
>> }
>> 1
>> 2
>>
>> Terry Smith wrote:
>>> Ok - I know how to get the fields of an Openstruct object like so
>>>
>>> class OpenStruct
>>>   def fields
>>>     @table.keys.map{|k| k.to_s}
>>>   end
>>> end
>>>
>>> a = OpenStruc.new()
>>> a.foo = 1
>>> a.bar = 2
>>>
>>> a.fields -> ["foo", "bar"]
>>>
>>> Great - ok how do I WORK with these once I have them?
>
> Just a remark: if your processing is mainly bases on keys this way 
> then a Hash might the better data structure.  IMHO an OpenStruct is 
> best used when you are lazy or do not know all the fields that you are 
> going to use beforehand.  I find this especially useful during 
> development, you can stuff in more and more fields but maybe later 
> change it to a regular class (or Struct generated class).
>
Hi Robert,
I had a similar experience with using OpenStruct and Hashes and in the 
end, I derived my class from OpenStruct (build up a hash within the 
contructor and create object with 'super()'). But what do you exactly 
mean by 'Struct generated class'? Is there a smart way of creating 
abstract classes (without deriving or explicit coding) from Structs?

regards
ralf