From: Robert Klemme <shortcutter@...>
Date: 2010-02-05T21:06:58+09:00
Subject: Re: Some noob questions

On 02/05/2010 12:50 PM, Albert Schlef wrote:
> Robert Klemme wrote:
>> On 05.02.2010 00:10, Albert Schlef wrote:
>>> Robert Klemme wrote:
>>>>     File.foreach(file).each_slice 2 do |name, pwd|
>>> How is it better than 'File.open(file).each_slice' ?
>> It closes the file handle properly which your variant doesn't do.
> 
> You mean, that in my version the file isn't closed till the file object 
> gets destroyed by the garbage collector?

Exactly.

> I see.
> 
> (I assume the enumerator returned by foreach() mimics foreach()'s 
> behaviour; that is, that it closes the file after the last iteration.)

It does not _mimic_ the behavior, it _uses_ it!!

irb(main):001:0> class X
irb(main):002:1> def self.foreach
irb(main):003:2> if block_given?
irb(main):004:3> puts "open"
irb(main):005:3> yield 123
irb(main):006:3> puts "close"
irb(main):007:3> else
irb(main):008:3* Enumerator.new(self, :foreach)
irb(main):009:3> end
irb(main):010:2> end
irb(main):011:1> end
=> nil
irb(main):012:0> X.foreach {|x| p x}
open
123
close
=> nil
irb(main):013:0> X.foreach.map {|x| x + 10000}
open
close
=> [10123]
irb(main):014:0>

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/