From: Robert Klemme <bob.news@...>
Date: 2004-12-31T04:26:43+09:00
Subject: Re: seeking hints for fast io


"Eric Hodel" <drbrain@segment7.net> schrieb im Newsbeitrag 
news:A589DDC3-5A8F-11D9-8CD7-000D93436DA0@segment7.net...

> On 30 Dec 2004, at 03:04, jm wrote:
>
> > I have a class which holds data while it's being manipulated. The
> > trouble is that I call to_s() quite a few times printing the resulting
> > data to a file. This increases the run time of the script a surprising
> > amount raising the runtime from about 6 minutes to about 8 and a half.
> > The code looks roughly likely the following,
> >
> > class Example
> > .
> > .
> >  def to_s
> >    sout << "a=#{@a}"
> >    sout << "b=#{@b}"
> >    sout.join("\n")
> >  end
> > end
> >
> > # in main
> > File.open(outfile,File::CREAT|File::RDWR|File::APPEND) do |fp|
> >  the_data.each do |d|
> >    fp.puts d
> >    fp.puts   # add blank line
> >  end
> > end
> >
> > Anyone care to suggest a way to speed this up? Is it faster to
> >
> >  sout << "a=" + @a
> >
> > instead of
> >
> >   sout << "a=#{@a}"
>
> Probably not, String#+ creates new strings, String#<< appends to an
> existing string

This is quite simple and avoids the unnecessary string interpolation.  I 
guess it'll be faster:

sout << "a=" << @a

Kind regards

    robert