From: Robert Klemme <bob.news@...>
Date: 2003-09-19T17:37:22+09:00
Subject: Re: Why IO#readlines does'nt accept a Regexp?


"Sabby and Tabby" <sabbyxtabby@yahoo.com> schrieb im Newsbeitrag
news:f5a79bf2.0309181614.1b288fb7@posting.google.com...
> "Robert Klemme" <bob.news@gmx.net> wrote:
>
> > For large Files this is more efficient:
> >
> > words=[]
> > IO.foreach("myfile") do |line|
> >   words.push( *line.scan( /\w+/oi ) )
> > end
>
> The /oi modifiers aren't necessary.

Granted.  I just grew used to putting "o" in there whenever the rx doesn't
change over time.  Kind of a documentation thingy.

> > If you have many repeating words you can save even more mem:
> >
> > cache = Hash.new {|h,k| h[k]=k}
> > words = []
> >
> > IO.foreach("myfile") do |line|
> >   words.push( *( line.scan( /\w+/oi ).map {|w| cache[w]} ) )
> > end
>
> The #map isn't doing what you think it is doing.  To remove repeating
> words from the list:

It does exactly what I think it's doing. :-)  I don't want to remove
repeated words from the list but replace all identical strings with the
same *instance* to save memory.  map fit's the job perfectly.  Of course,
you could use collect also... :-)

Regards

    robert