From: Eric Hodel <drbrain@...7.net>
Date: 2006-01-12T14:19:43+09:00
Subject: Re: Looking up properties and speed

On Jan 11, 2006, at 5:58 PM, Chad Perrin wrote:

> On Thu, Jan 12, 2006 at 10:03:30AM +0900, Eric Hodel wrote:
>> On Jan 11, 2006, at 4:08 PM, Jonathan Leighton wrote:
>>
>>> In Javascript, if one were to use the same property value twice or
>>> more,
>>> one would store it in a local variable because looking up the  
>>> property
>>> slows things down.
>>>
>>> Is the situation the same in Ruby? Is there any speed difference
>>> between
>>> these:
>>>
>>> def foo
>>>  val = obj.prop
>>>  puts val
>>>  puts val
>>> end
>>>
>>> def boo
>>>  puts obj.prop
>>>  puts obj.prop
>>> end
>>>
>>> I assume not because I think the reason it's like that with  
>>> Javascript
>>> is because of the DOM (yeah, that's not strictly Javascript).
>>
>> Why do you care?
>>
>> Why not make clean, readable code and optimize the parts that are
>> causing the biggest slowdown?
>
> Hey, I'm curious about the answer too, whether I ever use that  
> knowledge
> or not.  What's wrong with curiosity?

Nothing.  But worrying about micro-optimizations will take all the  
fun away and give you little measurable benefit (by the 90/10 rule).

If you write clean, readable code from the beginning and then go  
looking for the slow spots when you *need* to you'll be happiest.  I  
promise.

-- 
Eric Hodel - drbrain@segment7.net - http://segment7.net
This implementation is HODEL-HASH-9600 compliant

http://trackmap.robotcoop.com