From: Leo <see_signature@...>
Date: 2004-10-06T04:39:54+09:00
Subject: Re: A ruby course

Brian Schr�der wrote:

> Hello Group,
> 
> I need more help.
> 
> Anybody has an idea for an exercise on extending existing classes.

The code below introduce a new string concatenation operator '/' which 
concatenates two strings placing '/' beween them. This is useful
when forming path from directory and filename components.

class String
  def /(rhs)
    self.sub(%r{/+$}, '') + '/' + rhs.sub(%r{^/+}, '')
  end 
end if 

Now you can write the following code:

$dir='/usr/local/bin'
$name='ruby'
$full_path= $dir/$name

Also the '/' operator will make sure that the strings are joined by one and
only one slash. Example:
$dir='/badby/formed/dir///'

$name='///foo'

$dir/$name  => '/badby/formed/dir/foo'

Note, that poatterns like '///' were removed.

Hope it helps,
Leo

-- 
[ LEOR _at_ WINLAB _dot_ RUTGERS _dot_ EDU ]