From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2005-06-18T00:03:24+09:00
Subject: Re: Super-scalar Optimizations

On Fri, 17 Jun 2005, Gavin Kistner wrote:

> On Jun 17, 2005, at 6:40 AM, Robert Klemme wrote:
>> Even more so: what's the point of a loop that is alway run only once?
>
> Er, the loop doesn't run once, only the initialization code. The loop runs 
> forever.
>
>
> On Jun 17, 2005, at 6:11 AM, Devin Mullins wrote:
>> And wouldn't it be faster still just to pull foo = bar out of the while 
>> loop? :)
>
> I actually flubbed the example slightly. It should have been:
>
>  already_run = false
>  while true
>    do_something( )
>    foo = bar if !already_run
>    already_run = true
>  end
>
> Where "do_something()" was actually about 15 lines of code. The alternative 
> would have been:
>
>  do_something( )
>  foo = bar
>  while true
>    do_something( )
>  end
>
> which is not very DRY when do_something( ) is a large block of code.

sure it is - block being the key word here:

   do_something = lambda {|arg|
     ... 15 lines of code
     true
   }

   do_something[arg] and (foo = bar) and loop{ do_something[arg] }


pulling out little blocks of code that are re-used by can't be methods due to
context senstive behaviour or because they are just too small is what lambda
abstraction is for ;-)

cheers.

-a
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