On Fri, Nov 28, 2008 at 1:17 PM, Student <[EMAIL PROTECTED]> wrote: > Performance is one of those nasty things that can go from being a non- > issue to THE issue (next to correctness) in the blink of an eye. I am > curious, however. How much total performance difference did this > change make? I'm betting <1%. Yeah, this seems like premature optimization, if this were the only reason. Rspec does not call class << foo nearly 10000 times. Even if rspec did use class << foo 10000 times (each of which can define multiple methods), it would make 0.x seconds of a difference in the worst case (each class << object block only defines one method) and 0.0x seconds difference in the best case (one object with 10000 methods defined in it).
http://gist.github.com/30285 Here are my numbers where method is defined on a single object 10000 times: http://gist.github.com/raw/30285/a1731a82a0a59ec127b799ddb3b22763e9d06dd4 Heres another interesting benchmark where method is defined on 10000 objects 1 time: http://gist.github.com/raw/30285/a99305dbeef2aed8453add68a5197cff3418bb69 > > Nathan > > David Chelimsky wrote: >> On Thu, Nov 27, 2008 at 8:17 PM, Mark Wilden <[EMAIL PROTECTED]> wrote: >>> On Thu, Nov 27, 2008 at 5:57 PM, Brian Takita <[EMAIL PROTECTED]> >>> wrote: >>>> I'm wondering if this is a discussion about taste. >>> I think you're right. I've been using the 'def self.foo' style in various >>> languages for almost 20 years, so of course it feels more natural to me. >>> These languages (except for Smalltalk) had nowhere near the metaprogramming >>> capability nor 'objects all the way down'-ness of Ruby, and 'class << self' >>> is one of those things. >>> >>> ///ark >> >> FWIW, the blog that led to this discussion suggested a performance >> impact as well. As RSpec has gotten dinged for being slower than >> alternatives, that interested me, so I did a little experiment def'ing >> methods 10k times with def self.method and class << self; def method >> .... >> >> def self.method ran an average of 10% faster. >> >> Based on just that, I've all but eliminated class << self from rspec in git. >> >> Crazy? > > > On Nov 25, 8:52 am, "David Chelimsky" <[EMAIL PROTECTED]> wrote: >> On Tue, Nov 25, 2008 at 8:39 AM, Zach Dennis <[EMAIL PROTECTED]> wrote: >> > On Tue, Nov 25, 2008 at 9:38 AM, Zach Dennis <[EMAIL PROTECTED]> wrote: >> >> On Tue, Nov 25, 2008 at 8:41 AM, Matt Wynne <[EMAIL PROTECTED]> wrote: >> >>> Sorry, I know this is off-topic, but I'd really like to know what the >> >>> revered ruby-hackers who read this list think. >> >> >>> See >> >>>http://ozmm.org/posts/class__self_is_harmful.html >> >> >>> I have adopted class << self, partly from reading RSpec and Cucumber's >> >>> code >> >>> as I learn Ruby. I personally think of class methods (or 'static' >> >>> methods) >> >>> as being in a kind of 'holding pen' waiting to be factored off onto a >> >>> proper >> >>> class of their own, so I rather like the clear way you can group them in >> >>> a >> >>> 'nameless' metaclass ready for the exit door. >> >> >>> I also really like the clarity of seeing the invisible metaclass for >> >>> what it >> >>> is. >> >> >>> What do people think? How can this be harmful? >> >> > I forgot to add it is considered harmful because it can so easily be >> > abused and make readability of the code very difficult to understand. >> > Especially when doing meta-meta programming. :) >> >> >> I think the issue is that people are using class << self to access the >> >> virtual class when they don't need it. I've seen code where you have >> >> to scroll to see all of the methods implemented inside of class << >> >> self. Adding methods to a virtual class does make method dispatching >> >> in ruby less efficient, but I don't think enough to render it >> >> non-usable. >> >> >> The virtual class of an object (class or instance alike) gives you the >> >> ability to modify the object in ways that a simple class method >> >> usually does not allow. For example, if you want to break down a class >> >> method into a couple of methods, but you don't want to support all of >> >> the methods as a public API. Here you can use class << self to >> >> privately scope some of those helper methods that you just decomposed. >> >> >> My rule of thumb is to use it when I can't easily achieve the same >> >> result using other mechanisms, but not to use it just cause'. >> >> One thing Chris points out in his blog is that 'def self.method_name' >> is perfectly fine, and that it makes refactoring easier. My experience >> is different, because I'm often searching for methods with 'dev >> method_name' - this is actually one of the reasons I have preferred >> 'class << self'. >> >> That said, I'm all for speeding things up where we can, so I'll be >> looking into this in rspec. I just found 22 uses of 'class << self' in >> rspec. Sometime soon I'll see how many of them I feel I can get rid >> of. >> >> Cheers, >> David >> >> >> >> >> >> >> -- >> >> Zach Dennis >> >>http://www.continuousthinking.com >> >>http://www.mutuallyhuman.com >> >> > -- >> > Zach Dennis >> >http://www.continuousthinking.com >> >http://www.mutuallyhuman.com >> > _______________________________________________ >> > rspec-users mailing list >> > [EMAIL PROTECTED] >> >http://rubyforge.org/mailman/listinfo/rspec-users >> >> _______________________________________________ >> rspec-users mailing list >> [EMAIL PROTECTED]://rubyforge.org/mailman/listinfo/rspec-users > _______________________________________________ > rspec-users mailing list > rspec-users@rubyforge.org > http://rubyforge.org/mailman/listinfo/rspec-users > _______________________________________________ rspec-users mailing list rspec-users@rubyforge.org http://rubyforge.org/mailman/listinfo/rspec-users
