From: Robert Klemme <bob.news@...>
Date: 2004-09-28T16:29:24+09:00
Subject: Re: keep changes in string outside of scope?


"David A. Black" <dblack@wobblini.net> schrieb im Newsbeitrag
news:Pine.LNX.4.44.0409271452500.8281-100000@wobblini...
> Hi --
>
> On Tue, 28 Sep 2004, David A. Black wrote:
>
> >   thestring.sub!(/\d{5}/) {|x| "#{x},"}
>
> Amendment: as James G. suggested, use gsub! if you have more than one
> in one string :-)  Also make sure that you have no street numbers with
> five digits in a row.

The block variant isn't necessary in this case.  A remark about
efficiency:

require 'benchmark'

REP = 1000

thestring = ("foo 12345 bar baz" * 100).freeze

Benchmark.bm(15) do |b|
  b.report "direct" do
    REP.times { thestring.gsub(/\d{5}/, ',\\&') }
  end

  b.report "direct group" do
    REP.times { thestring.gsub(/(\d{5})/, ',\\1') }
  end

  b.report "block" do
    REP.times { thestring.gsub(/\d{5}/) {|m| ",#{m}"} }
  end
end

                     user     system      total        real
direct           0.516000   0.000000   0.516000 (  0.527000)
direct group     0.546000   0.000000   0.546000 (  0.537000)
block            1.829000   0.000000   1.829000 (  1.844000)


Kind regards

    robert