From: Gennady Bystritsky <Gennady.Bystritsky@...>
Date: 2006-05-22T01:43:01+09:00
Subject: Re: rubynuby - confused by method name "inject"

Ruby's inject() lets you do amazing things very expressively. I first
got into inject() when realized how easy it makes getting a class by its
fully qualified name:
 
klass = fully_qualified_name.split('::').inject(Module) { |_module,
_symbol| 
  _module.const_get(_symbol) 
}

instance = klass.new

In this example name "inject" totally corresponds to what it is doing
here. To me at least.

Sincerely,
Gennady.

> -----Original Message-----
> From: Robert Klemme [mailto:shortcutter@googlemail.com] 
> Sent: Sunday, May 21, 2006 8:59 AM
> To: ruby-talk ML
> Subject: Re: rubynuby - confused by method name "inject"
> 
> 2006/5/21, ReggW <me@yourhome.com>:
> > Jeff Pritchard wrote:
> > > Can anybody explain to me how the Enumberable#inject method is
> > > "injecting" something into something?  I find it very 
> difficult remember
> > > method names when I don't "get" them.  So far in Ruby, 
> "inject" takes
> > > the cake for least understandable method name (with my 
> own particular
> > > convoluted gray matter).
> >
> > I agree!!!!
> >
> >
> > I have it marked in my "Ruby notes", as "Don't use".
> > I do this so that when I come across it again, I won't spend 2 hours
> > trying to make sense out of it's purpose.
> 
> Granted that it may take some time to understand it and to recognize
> its power (took me a while, too), but - once you grokked it you'll be
> amazed how much you can do with it.  A lot - if not all - methods in
> Enumerable can be elegantly implemented with inject.  Try it out!
> Also, when searching the archives you'll find quite a few postings
> that show how something can be done with inject and often it's more
> elegant than other methods.  Just compare the example that has been
> shown in this thread with the version using each:
> 
> sum = 0
> enum.each {|x| sum += x}
> sum
> 
> enum.inject(0) {|sum, x| sum + x}
> 
> Kind regards
> 
> robert
> 
> 
> -- 
> Have a look: http://www.flickr.com/photos/fussel-foto/
> 
>