[LRUG] [Chat] IronRuby

[Paul Doerwald]

I've always thought that you should use exceptions for "exceptional"  
cases. In the normal or alternate cases, the exception won't happen.  
Save, for instance, has a normal case, save the record, and an  
alternate case, there is a validation problem that has caused us to  
be unable to save the record. You could argue a third "exceptional"  
case, which would be that the database (due to constraints or out-of- 
disk-space, or some other db-specific problem) has caused the system  
to be unable to save the record even though the validations have  
passed. (This is not supported because DHH/ActiveRecord doesn't  
believe that databases are anything more than a persistent storage).

In the example you showed in pastie, by the looks of it, those are  
all alternate cases, not exceptional ones. Exceptional would be if  
you try to kick, pamper or kill him, and he's not there.

Paul.



On 24-Jul-07, at 10:13 AM, Pratik Naik wrote:

> It's not about one way being better than the other. It just reflects
> how you persue things. When you take rescue approach, your main code
> is only the perfect use case, instead of handling "things that could
> go wrong" in the same block.
>
> I believe it also helps you keep the logic seperate for perfect use of
> an API and when someone screws up.
>
> We all know the difference between save and save! So that example is
> not very helpful.
>
> But imagine something like http://pastie.caboo.se/81719
>
> I'm not saying it's a better way. I'm just saying that it's not a
> wrong way either.
>
>> Why is that better than
>>
>>   def create
>>     @person = Person.new(params[:person])
>>     if @person.save
>>       redirect_to :index
>>     else
>>       render :action => "new"
>>     end
>>   end
>>
>> ?
>>
>>
>> --
>> * J *
>>   ~
>> _______________________________________________
>> Chat mailing list
>> Chat at lists.lrug.org
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>>
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