DIP 1019--Named Arguments Lite--Final Review

[bachmeier]

On Friday, 23 August 2019 at 17:42:14 UTC, H. S. Teoh wrote:

> But this:
>
> 	foo(x: 4, y: 8, z: 9,
> 		screen: scr1, widget: wg2,
> 		options: opts, menu: menu3);
>
> is no worse than this:
>
> 	FooParams params;
> 	params.x = 4;
> 	params.y = 8;
> 	params.z = 9;
> 	params.screen = scr1;
> 	params.widget = wg2;
> 	params.options = opts;
> 	params.menu = menu3;
> 	foo(params);

What that leads to is this:

foo(x: 4, y: 8, z: 9,
	screen: scr1, widget: wg2,
	options: opts, menu: menu3);
foo(x: 4, y: 8, z: 9,
	screen: scr2, widget: wg2,
	options: opts, menu: menu3);
foo(x: 4, y: 8, z: 9,
	screen: scr1, widget: wg1,
	options: opts, menu: menu3);

You've got a combination of extreme verbosity, hard-to-read code, 
and a prolific bug generation machine. The answer to that is to 
start currying function arguments or write a customized function 
that calls foo while holding fixed certain parameters. It's 
extremely clear when you change a single parameter in a struct. 
And nobody had to learn yet another piece of syntax in order to 
read D code. The best anyone can say is that this is not harmful 
in simple cases.