From: "ako..." <akonsu@...>
Date: 2006-08-27T12:05:11+09:00
Subject: Re: map and join or inject?

thanks, i did not know that one can count objects using ObjectSpace.

it looks like map+join use fewer objects than inject. even though map
creates a whole new array. i would expect inject to use fewer objects.
strange...

konstantin

Erik Veenstra wrote:
> ----------------------------------------------------------------
>
>  $ vi test.rb ; cat test.rb
>  GC.disable
>
>  1000.times do
>    (1..1000).map{|s| s.to_s}.join("")
>    #(1..1000).inject(""){|r, s| s.to_s; r}
>  end
>
>  count   = 0
>  ObjectSpace.each_object do
>    count += 1
>  end
>  p count
>
>  $ ruby test.rb
>  1003392
>
> ----------------------------------------------------------------
>
>  $ vi test.rb ; cat test.rb
>  GC.disable
>
>  1000.times do
>    #(1..1000).map{|s| s.to_s}.join("")
>    (1..1000).inject(""){|r, s| s.to_s; r}
>  end
>
>  count   = 0
>  ObjectSpace.each_object do
>    count += 1
>  end
>  p count
>
>  $ ruby test.rb
>  2001392
>
> ----------------------------------------------------------------
> 
> gegroet,
> Erik V. - http://www.erikveen.dds.nl/