From: Erik Veenstra <erikveen@...>
Date: 2006-08-15T02:14:10+09:00
Subject: Re: hash.keys and hash.values

> Here's another solution - maybe it's even more efficient as
> it doesn't need the transposing:

Well, a quick benchmark... No, it isn't more efficient. Neither
time-wise, nor memory-wise.

gegroet,
Erik V. - http://www.erikveen.dds.nl/

----------------------------------------------------------------

 $ cat test.rb
 require "ev/ruby"

 GC.disable

 hash    = {}

 1000.times do |n|
   hash[n] = n*n
 end

 case ARGV.shift
 when "transpose"
   bm do
     1000.times do
       keys, values      = hash.to_a.transpose
     end
   end
 when "inject"
   bm do
     1000.times do
       keys, values      = hash.inject([[],[]]){|(ks,vs),(k,v)| [ks <<
k, vs << v]}
     end
   end
 else
   raise "uh?"
 end

 puts meminfo

 $ ruby test.rb transpose
 VmSize:    58284 kB
        CPU    ELAPSED      COUNT  CPU/COUNT   LABEL
   1.020000   1.153397          1   1.020000   "test.rb:13"

 $ ruby test.rb inject
 VmSize:   146676 kB
        CPU    ELAPSED      COUNT  CPU/COUNT   LABEL
   2.700000   2.826171          1   2.700000   "test.rb:19"

----------------------------------------------------------------