From: Joel VanderWerf <vjoel@...>
Date: 2006-04-18T03:39:17+09:00
Subject: Re: Refactoring (#75)

Jim Weirich wrote:
> Dave Burt wrote:
>> Hi Ruby Quiz,
>>
>> Sorry, this is likely to be rather uninteresting, 
> 
> Actually, I find it very interesting ... but then, you have to consider 
> my tastes. :)
> 
>> Refactoring 1: Merge Redundant Exception Handlers
>> /You have a series of exception handling blocks with identical 
>> handlers./
>> *Merge the code into a single exception handling block.*
>>
>> Thus:
>>
>>   begin
>>     foo
>>   rescue Exception => e
>>     barf e
>>   end
>>   begin
>>     bar
>>   rescue Exception => e
>>     barf e
>>   end
>>
>> Becomes:
>>
>>   begin
>>     foo
>>     bar
>>   rescue Exception => e
>>     barf e
>>   end
> 
> You need to be careful here.  If 'barf' does not thrown an exception, 
> but merely prints an error message of some kind, then the refactoring 
> changes the behavior (which technically, makes it *not* a refactoring).

What about using another method and yield here?

def barf_on_exception
  yield
rescue Exception => e
  barf e
end

barf_on_exception {foo}
barf_on_exception {bar}


Or even:

def on(ex, m)
  yield
rescue ex => e
  send m, e
end

on(Exception, :barf) {foo}
on(Exception, :barf) {bar}

But I'm not sure that it's really better than the original exception clause.

-- 
      vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407