From: Joel VanderWerf <vjoel@...>
Date: 2006-11-17T06:57:52+09:00
Subject: Re: #returning and #tap

Eric Hodel wrote:
> On Nov 15, 2006, at 5:40 PM, Joel VanderWerf wrote:
>> Eric Hodel wrote:
>> ...
>>> So... it usually doesn't save any lines, it adds typing, it hides the 
>>> object you're returning in the middle of a statement and it is 
>>> significantly more expensive to execute[1].  (Oh, but maybe, in some 
>>> cases, it might save you one or two lines of code.)
>>> No thanks.
>>> I don't think that makes it more rubyish.  Every time I've 
>>> encountered #returning in Rails I've found it decreased the 
>>> readability of the code and uselessly increased the complexity.  
>>> (Wait, now what does this return? oh, yeah, way up there.)
>>
>> This variant saves typing and IMO is more idiomatically ruby:
>>
>> class Object
>>   def then
>>     yield(self)
>>     self
>>   end
>> end
>>
>> def foo
>>   @foo ||= Foo.new.then do |f|
>>     f.bar = "bar"
>>   end
>> end
> 
> $ wc
> [...]
>        5      12      67
> 
>> Otherwise you have to do this:
> 
> I would write it:
> 
> def foo
>   return @foo if @foo
>   @foo = Foo.new
>   @foo.bar = 'bar'
>   @foo
> end
> 
> $ wc
> ...
>        6      14      77
> 
> Ten characters and one line more typing, but less punctuation.  (And 
> those ten extra characters will be mostly be handled by my tab key.)

But you have to type @foo _five_ times, instead of once. Oh, well. It's 
a matter of taste.

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