DIP 1019--Named Arguments Lite--Community Review Round 2

[Aliak]

On Thursday, 6 June 2019 at 20:04:15 UTC, Walter Bright wrote:
>    discovered as necessary behavior. Consider:
>
>     void snoopy(T t, int i, S s);     // A
>     void snoopy(S s, int i = 0; T t); // B
>
> and calling it:
>
>     S s; T t; int i;
>     snoopy(t, i, s); // A
>     snoopy(s, i, t); // B
>     snoopy(s, t); // error, neither A nor B match
>     snoopy(t, s); // error, neither A nor B match
>     snoopy(s:s, t:t, i:i); // error, ambiguous
>     snoopy(s:s, t:t); // B
>     snoopy(t:t, s:s); // B
>     snoopy(t:t, i, s:s); // A
>     snoopy(s:s, t:t, i); // A

Trying to understand why the last two call A and are not 
ambiguous?

> One issue would be order of evaluation: would the arguments be 
> evaluated in the
> lexical order of the arguments, or the lexical order of the 
> parameters?

Arguments would provide consistency but parameters feel more 
intuitive from a user perspective. But yeah, hard to say!