From: "David A. Black" <dblack@...>
Date: 2004-12-08T22:46:32+09:00
Subject: Re: Using yield

Hi --

On Wed, 8 Dec 2004, Robert Klemme wrote:

>
> "David A. Black" <dblack@wobblini.net> schrieb im Newsbeitrag
> news:Pine.LNX.4.44.0412071110500.21344-100000@wobblini...
>> Hi --
>>
>> On Tue, 7 Dec 2004, Robert Klemme wrote:
>>
>>> 13:21:36 [robert.klemme]: ruby yield-vs-block.rb
>>>                           user     system      total        real
>>> yield                 0.250000   0.000000   0.250000 (  0.249000)
>>> block                 0.125000   0.000000   0.125000 (  0.124000)
>>> 13:21:44 [robert.klemme]: cat yield-vs-block.rb
>>>
>>> require 'benchmark'
>>> include Benchmark
>>>
>>> REP = 100000
>>>
>>> def bl_yield(n)
>>>   n.times {|i| yield i}
>>> end
>>>
>>> def bl_fwd(n,&b)
>>>   n.times(&b)
>>> end
>>
>> Those aren't equivalent, though.  The second one would have to be:
>>
>>   n.times {|i| b.call(i) }
>>
>> to compare the two idioms directly.
>
> Hm, I'm not sure I agree here.  My point was to compare performance of two
> idioms achieving that a block handed to a method is called from another
> method called within that method.  You are right with respect to the
> invocation chain though.

I think we're talking about different sets of "two idioms", but I see
what you mean about your set.  As for....

>> Or am I behind the times on automatic propagation?  (But even in that
>> case I don't think supplying block #1 to method #2 is the same as
>> yielding to block #1 during method #1.)
>
> What exactly do you think is the difference here?  (Apart from performance
> of course)

... there's something nagging in my mind that I can't quite nail down,
having something to do with argument parsing, I think.  It's probably
illusory.  If I manage to figure out what it is, I'll post it :-)


David

-- 
David A. Black
dblack@wobblini.net