Re: Custom Blocks

[KennyTM~]

On Aug 12, 10 10:25, Robert Jacques wrote:
On Wed, 11 Aug 2010 17:54:35 -0400, Tomek Sowiński <j...@ask.me> wrote:
Robert Jacques napisał:

I was thinking something like this:

void fun(int x, int y, int z, delegate void(int, int, int) dg)

fun(x, y, z, a, b, c) { body }

|
V

fun(x, y, z, (a, b, c) { body });

Mixing function args with delegate args makes me think of foreach:

fun(x, y, z, (a, b, c) { body }); <=> fun(a, b, c; x, y, z) { body }

All great, but if there's no remedy for the return WTF, I'd leave this
(nice) feature in the drawer.

void foo() {
fun(a, b, c; x, y, z) {
return; // who returns?
}
}


Tomek

Fun does. This is the same as function/delegate literals today.
Of course, putting a return statement inside a foreach block is probably
a buggy edge case right now; sometimes it causes the parent scope to
return and sometimes it doesn't compile.

This is an unacceptable buggy edge case. Consider the already-working code

   int find_three(int[] arr) {
     foreach (i, x; arr) {
       if (x == 3)
         return i;
     }
     return -1;
   }

If I replace the foreach with a custom block e.g.

   int find_three_retro(int[] arr) {
     foreach_retro (i, x; arr) {
       if (x == 3)
         return i;
     }
     return -1;
   }

then suddenly the function doesn't work anymore. It's better not to 
provide a feature inconsistent with other parts of the language.