member arguments in D? (solution for Phobos

[DisForDave]

downs Wrote:

> Nick Sabalausky wrote:
> > "Daniel Keep" <daniel.keep.lists at gmail.com> wrote in message 
> > news:gt159p$1bq0$1 at digitalmars.com...
> >>
> >> Penguin wrote:
> >>> What do you think about:
> >>>
> >>> class Foo {
> >>>
> >>>    int a;
> >>>    float b;
> >>>
> >>>    this( member a, member b ) {
> >>>
> >>>    }
> >>>
> >>> }
> >>>
> >>> instead of:
> >>>
> >>> class Foo {
> >>>
> >>>    int a;
> >>>    float b;
> >>>
> >>>    this( int a, float b ) {
> >>>       this.a = a;
> >>>       this.b = b;
> >>>    }
> >>>
> >>> }
> >> I don't know that saving a few (very simple) lines of code is worth
> >> adding a new keyword and magic behaviour to ctor arguments.
> >>
> >> If you really wanted to just do that, you could probably write a mixin
> >> to take care of it.
> >>
> > 
> > I just happen to already have such a thing in my bag-o-tricks. See 
> > attachment.
> > 
> > Usage:
> > ----
> > mixin(initMember!(someVar));
> > mixin(initMember!(a, b, c));
> > ----
> > 
> > Turns Into:
> > ----
> > this.someVar = someVar;
> > this.a = a;
> > this.b = b;
> > this.c = c;
> > ----
> > 
> > 
> > 
> 
> I _also_ have something for this for Phobos (in tools.base), but it's intended for simple constructors.
> 
> class Foo {
>   int a; float b;
>   mixin This!("a, b");
> }
> 
> Or to add some instruction: mixin This!("a; #b = 0f; ");
> 
> Or to add a super call and defaults: mixin This!("a, super(b=0f)");


but this is something the compiler should really be dealing with, it's such a common programming practice (the fact so many people have their own hacks for it is testament to this)

i think it's worth a new keyword