between and among: worth Phobosization?

[Lionello Lunesu]

On 12/17/13, 4:38, Andrei Alexandrescu wrote:
> bool between(T, U1, U2)(T v, U1 lo, U2 hi)
> {
>      return v >= lo && v <= hi;
> }

The expression a<b<c is not ambiguous in D. We could make it do what 
people expect.


> uint among(T, Us...)(T v, Us vals)
> {
>      foreach (i, U; Us)
>      {
>          if (v == vals[i]) return i + 1;
>      }
>      return 0;
> }

"in"?

assert("a" in ["a":1, "b":1]);

Again, with little compiler magic we could allow that to be written as

assert("a" in ["a", "b"]);

Note that I'm not advocating for O(n) "in" for regular arrays, but 
merely for the compiler to recognize the "in []" pattern and Do The 
Right Thing.

L.