this is almost a workaround for the lack of named parameters

[J]

On Wednesday, 27 March 2013 at 03:29:24 UTC, Timothee Cour wrote:
>>>Interesting, the "doesn't not support passing the arguments 
>>>out of order." can be seen either as a (temporary or not) 
>>>implementation >>limitation OR as a feature.
>
> Named parameters are only interesting if we can skip some 
> optional parameters.

I'd say named parameters are *more* interesting with skipping and 
re-ordering, but still incredibly valuable even without.  Let us 
get them in people's hands first (and start the addiction process 
going...bwahahaha!)

Let people experience first hand how awesome they are in a quick, 
doable form.

(Feel free to contribute code that implements those skipping and 
re-ordering features...)


Status update: I fixed the only known bug, and added a feature.

a. Named parameters now flow into variadic template arguments 
without a hitch.

In other words, this compiles:

void test(A...)(A a) {}
void main ()
{
     test(b: 33.3
          c: 44.4);
}


b. There is an name-matching escape mechanism now. It uses 
_underscores. If your function looks like:

void f(int a, int _b) {}

then you can call it like this:

f(a:1, anyLabelYouWant: 3);

(Actually this was necessitated by how dmd treats variadic actual 
arguments; it calls them _param_0, _param_1, ..., internally. I'm 
still going to call this escape-mechanism a feature, though.)


Here's the latest (see the named_parameters branch specifically)

https://github.com/glycerine/dmd/tree/named_parameters

This passes all tests.

Try it out. Try and break it.