On Thu, Jun 7, 2012 at 2:27 PM, Patrick Walton <[email protected]> wrote:
> On 6/7/12 2:20 PM, Gareth Smith wrote:
>
> If you allow all block lambdas to have early returns with "ret", then this:
>
> fn f() {
> for int::range(1, 10) |i| {
> ret i;
> }
> }
>
> Has a very different meaning from:
>
> fn f() {
> int::range(1, 10) |i| {
> ret i;
> }
> }
>
> IMHO this is likely to be pretty confusing.
>
> Also, eliminating "do" makes this ambiguous:
>
> spawn() || {
> ...
> }
>
> Is ambiguous with bitwise-or. This is also ambiguous:
>
> spawn || {
> ...
> }
>
> In any case, I think this looks nicer:
>
> do spawn {
> ...
> }
To throw one other option out there, we do support breaking out of a
closure with the "fn@" closure syntax:
```
fn foo(x: int, f: fn(int)) {
f(x);
}
fn main() {
foo(5, fn@(x: int) {
#error("%?", x);
if x == 5 { ret }
#error("%?", x);
});
foo(6, fn@(x: int) {
#error("%?", x);
if x == 5 { ret }
#error("%?", x);
});
}
```
(As an aside, it sure would be nice if the fn@ closures inferred their types...)
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