From: Paul Lutus <nospam@...>
Date: 2006-11-30T02:45:22+09:00
Subject: Re: Need a range, but not getting it. . . .

Peter Bailey wrote:

> Jon Garvin wrote:
>> Try...
>> 
>> files = [ARGV].to_s
>> files.gsub!(/\-/, "..")
>> puts files
>> 
>> However, I *think* that ARGV is already a string? so that to_s in the
>> first line may be redundant.
>> 
>> Your problem was that, although gsub! (with the !) normally modifies the
>> receiver, 'files' wasn't the receiver (to_s was), so you weren't
>> actually changing 'files'.
> 
> Cool. That worked, Jon. Thanks. I don't quite understand it, though. I
> suppose you're right, that gsub was modifying to_s and not files, but,
> why was that? I thought that to_s was modifying files and then gsub was
> modifying that modified files. I guess I need to tame my dots, eh?

Some of the advice offered by Mr. Garvin was in error.

Remember these points:

1. ARGV is an array. If you want to provide more than one input argument,
you need to parse them:

ARGV.each do |arg|
  # do something here
end

But you do not normally want to collapse the array into a single string
using "ARGV.to_s"

Mr. Garvin's remark about the receiver:

>> Your problem was that, although gsub! (with the !) normally modifies the
>> receiver, 'files' wasn't the receiver (to_s was), so you weren't
>> actually changing 'files'.

Is mistaken in this case. In fact, file.to_s.gsub!(...) will change the
value of "files" if "files" is a string. In this case it is a string.


-- 
Paul Lutus
http://www.arachnoid.com