From: Edgardo Hames <ehames@...>
Date: 2004-10-06T03:38:04+09:00
Subject: Re: Extending existing classes (was: Re: A ruby course)

On Wed, 6 Oct 2004 03:29:35 +0900, Henrik Horneber <ryco@gmx.net> wrote:
> >> - extending String so you can tell it to remove cpp comments /* remove
> >> me */
> >
> > Extending string with something like remove_cpp_comments seems awkward
> > to me. In any usecase for this I'd rather have a class CppCode that I
> > can ask to remove_comments. (Or even better, to give me the source
> > without comments.)
> >
> > So my personal heuristic tells me not to extend in this case.
> 
> Now, the reason I was immediatly reminded of that remove_cpp_comments
> example is, that I wrote a small script some time ago, which used
> exactly this case. First, I implemented remove_cpp_comments in its own
> class (which was not called CppCode, but had the same intend), but out
> of curiosity (and because in ruby I can, dang it! :) ) I moved the
> remove_cpp_comments method to String. Turns out, the method got shorter
>  and somewhat clearer, at least to me. And I could write something like
> 
> source_code = IO.readlines(file).join("\n")
> source_code.strip_comments!
> # instead of source_code = CppCode.strip_comments( source_code)
> 
> .... you get the idea.
> 
> Even though the code became clearer on that level, I still have to agree
> with Brian that it is somehow dirty/awkward on a different level to
> extend String with such a method.
> 

I usually try not to do that kind of things. Then, for each new
lanaguage you are going to support, you should now add a
remove_#{lang}_comments to String. But then, when reading a given
source file you could remove comments that are not so in that
language.

Regards,
Ed
-- 
" Don't relax!  It's only your tension that's holding you together."