From: Joel VanderWerf <vjoel@...>
Date: 2002-09-16T12:25:28+09:00
Subject: Re: camelCaseTo_ruby_case.rb ??

dblack@candle.superlink.net wrote:
> Hi --
> 
> On Mon, 16 Sep 2002, Joel VanderWerf wrote:
> 
> 
>>Two comments:
>>
>>1. #gsub! has big teeth and will bite you:
>>
>>   "FooBar".decamel   # ==> nil
>>
>>It seems ok with #gsub instead of the first occurrence of #gsub!.
> 
> 
> How strange.  When I do this in irb, I get nil, as you say.  But when
> I run my little script:
> 
>   #!/usr/bin/ruby -wp
> 
>   BEGIN {
>     class String
>       def decamel
> 	gsub!(/\b[^\WA-Z]+[A-Z].*?\b/) do |x|
> 	  x.gsub!(/[A-Z][^\WA-Z]+/) {|s| "_" + s.downcase }
> 	  x.gsub!(/[A-Z][A-Z]+/)    {|s| "_" + s }
> 	  x
> 	end
>       end
>     end
>   }
> 
>   $_.decamel
> 
> 
> I get this (where odd-numbered lines are typed in and even ones are the
> output):
> 
>   someMethodOrOther
>   some_method_or_other
>   SomeClass
>   SomeClass
> 
> which is what I wanted.  I can't quite puzzle through why there would
> be that difference.

I guess -p calls #print, which prints $_, and ignores the value of the 
expression.