From: Daniel Berger <Daniel.Berger@...>
Date: 2005-08-19T03:31:41+09:00
Subject: Re: Idiomatic ruby version of this code?

why the lucky stiff wrote:
> Brock Weaver wrote:
> 
>> Here's my first solution:
>>
>> Dir.new("./").each do |file|
>>     if file.match(/mp3$/)
>>         File.rename(file, file.gsub(/mp3$/, 'temp'))
>>     elsif file.match(/temp$/)
>>         File.rename(file, file.gsub(/temp$/, 'mp3'))
>>     end
>> end
>>   
> 
> You could use the tertiary operator to switch file names, but the (exp 
> .. and .. or) is also nice for this kind of swapping thing.
> 
>  Dir["*.{temp,mp3}"].each do |file|
>    File.rename( file, file.gsub( /\w+$/ ) { |ext| ext == 'mp3' and 
> 'temp' or 'mp3' } )
>  end
> 
> If you don't want your extensions hardcoded everywhere, use an array:
> 
>  exts = ['temp', 'mp3']
>  Dir["*.{#{exts.join ','}}"].each do |file|
>    File.rename( file, file.gsub( /(\w+)$/ ) { exts.detect { |x| x != $1 
> } } )
>  end
> 
> _why
> 
> 

gsub and backreferences?  Why take that approach when File.basename is 
available?

def switch(old, new)
    Dir["*.#{old}"].each{ |file|
       new_name = File.basename(file, old) + "." + new
       File.rename(file, new_name)
    }
end

Regards,

Dan