From: Robert Klemme <shortcutter@...>
Date: 2008-07-30T16:33:10+09:00
Subject: Re: A couple of basic questions

2008/7/30 RichardOnRails <RichardDummyMailbox58407@uscomputergurus.com>:
> Hi,
>
> Q.1: I was processing file/dir names with the following snippet:
>
> Find.find(wd) do |item| # Subordinate file/directory fully-qualified
> names
>  if File.directory?(item)
>    # Process directory name
>    if item =~ /portfolio/i
>      item_saved = '  ' + item
>      item.gsub!(/portfolio/, 'position')
>
> When I saved item in item_saved without modification,  the gsub change
> both the item name as well as the saved name (because what was saved
> was a reference to item, not item's content).  So my work-around was
> to save a modified name. That doesn't seem like "The Ruby Way".
> What's a better way?

Leave item alone and store the new name in a new variable:

if ...
new_item = item.gsub(/portfolio/, 'position')

(notice the missing "!")

> Q. 2:  In that same snippet,  I made two substitutions:
>
>      item.gsub!(/portfolio/, 'position')
>      item.gsub!(/Portfolio/, 'Position')
>
> That's also a kluge.  But the following didn't compile:
>
>      item.gsub!(/([pP])ortfolio/, $1 + 'osition')

This cannot work because $1 is evaluated only once, i.e. before #gsub
is invoked.  You need something like Phlip suggested.

item.gsub /([pP])ortfolio/, '\\1osition'

> Is there a "Ruby Way" to reduce the redundancy?

Yes.

Cheers

robert

-- 
use.inject do |as, often| as.you_can - without end