Re: [Webmacro-devel] Is this a bug? More obscure #macro issues

[Marc P. <ma...@an...>]

On Sat, 26 Jul 2003 13:24:39 -0700, Brian Goetz <br...@qu...> wrote:

>> I'm not sure what we can do about this. I mistakenly thought #macro 
>> would have a separate context for its arguments, and as such changes to 
>> an outer variable would not suddently change the value of a differently 
>> named parameter to the macro.
>
> Nope, not how it works, nor how it was intended to work -- otherwise
> you couldn't have macros that modified their arguments.

That's why I said "mistakenly" in the above, and why I asked "Is this a 
bug".

>> So, is this a bug or a "feature"?
>
> Feature.  Just like C macros.  If you intend to have local variables,
> name them in such a way as to never conflict, just like in C.

Fine, and that's exactly what I suggested as the workaround. The point is, 
as much laboured before, that template writers will not get this. They are 
not C programmers.

Roll on #templet/#eval :)

> Macro-local variables would be nice -- want to add them?

Perhaps, although I'm more concerned with not having the values of 
arguments change because a global variable used as the value of that 
argument changed - i.e. snapshot the context somehow.

While macros have an optimisation advantage, I think this work would not be 
worthwhile when #templet is ready for prime time.

Marc

-- 
Marc Palmer
Contract Java Consultant/Developer
			
                        w a n g j a m m e r s

                 java and web software design
              experts with an ethical outlook

                   http://www.wangjammers.org