From: Joel VanderWerf <vjoel@...>
Date: 2009-02-14T01:29:45+09:00
Subject: Re: performance tips

Robert Klemme wrote:
> 2008/4/10 Joel VanderWerf <vjoel@path.berkeley.edu>:
>> Vince Forgetta wrote:
>>> Hi all,
>>>
>>> I've been using ruby for about 2 years, but only recently got around
>>> trying
>>> and learning it well.
>>>
>>> Is there some central repository I can get performance tips/discussions
>>> such
>>> as the one posted here:
>>>
>>> http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/158212
>> Instead of:
>>
>> lines = File.readlines('sometextfile').each {|l| l.chomp!}
>>
>> do this:
>>
>> lines = File.open "test" do |f|
>>  f.map {|line| line.chomp}
>> end
>>
>> That saves you from having the large string returned by #readlines.
> 
> ???  I could have understood if you argued that your solution avoids
> traversing lines twice but this statement is plain wrong:
> File.readlines never returned a single String.

Oops, I think possibly I meant File.read and map:

lines = File.read('sometextfile').map {|l| l.chomp!}

Thanks to you, Robert, and to Tom Link for pointing that out as well in 
an email.

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407