New syntax for string mixins

[Jacob Carlborg]

On 2010-12-16 21:35, Nick Sabalausky wrote:
> "Jacob Carlborg"<doob at me.com>  wrote in message
> news:iedpbg$3i0$1 at digitalmars.com...
>> On 2010-12-15 23:00, Nick Sabalausky wrote:
>>>
>>> I don't see why these shouldn't work:
>>>
>>> @"int foo;";
>>> return @("lhs " ~ op ~ " rhs");
>>>
>>> At least with just the "@" part of the proposal. Maybe the delegate thing
>>> might make it tricker, I dunno.
>>
>> My idea was actually to get rid of the strings where the code to be mixed
>> in is defined and to have a better syntax where it's used.
>>
>> The delegates are just a way of passing a block of code around. If you
>> just use it in place then maybe one could do like this:
>>
>> @(int foo;);
>> return @(lhs@(op)rhs);
>>
>
> Yea, my point was just that the "@..." stuff could work either way, with the
> string-based system or with your delegate-based one.
>
> I don't mean to come across like I'm ignoring or against the idea of the
> whole delegate aspect, and I understand that the main point of the OP is to
> replace the strings with delegates, but with the q{...} syntax and
> string-templating, I'm still struggling to see a big enough benefit compared
> to the status quo. I see that using delegates instead of strings could
> probably be made to work, but my questions are "For what benefit(s)?" and
> "Would those benefits be sufficient to warrant the change?" I'm not
> necessarily saying the answer is "no", but I'm unconvinced so far.
>
> And here's another thing: Suppose we got a Ruby/PHP-like syntax for
> embedding code substitutions directly into a string (which would have other
> useful applications besides mixins):
>
> auto name = "Joe";
> auto msg = "hello #{name}, whaddup?";
> mixin( q{ int #{name} = 7; } );
> Joe++;
>
> Would that eliminate much (or all) of the benefit of the delegate approach?

I guess using q{...} with string interpolation is very similar to the 
delegate approach. It just feels wrong passing around strings to 
represent code. I haven't though much about it but with delegates one 
could at lest hope for better help from the compiler validating the 
code. I don't know how IDEs will treat q{...} but with delegates you 
would get the full benefit of the IDE like autocompletion and similar 
features.

-- 
/Jacob Carlborg