If `do` is going away from being used as syntactic sugar to invoke
functions with closure arguments, would it be a possibility to use it here?
--
Ziad
On Wed, Dec 11, 2013 at 6:30 PM, Zack Corr <z...@z0w0.me> wrote:
> It could certainly be implemented now, if it was restrictive to builtin
> monad types - like `Option`. The real question would be what sort of syntax
> fits in with Rust. Would there be a new bind operator, or have `bind`
> instead of `let` in `do` blocks or just reuse let and have any option types
> be automatically deconstructed in the binding (yuck).
>
> For example using the first,
>
> fn str_larger_than_five(str: ~str) {
>> do {
>> val <- from_str("1");
>>
>> return val > 5;
>> }
>> }
>
>
> or perhaps a bind keyword would nicer (my preference, but requires an
> extra keyword):
>
> bind val = from_str("1");
>
> return val > 5;
>
>
> Of course the current usage of `do` would need to be removed in favour of
> another keyword.
>
>
>
> On Thu, Dec 12, 2013 at 10:55 AM, Brendan Zabarauskas <bjz...@yahoo.com.au
> > wrote:
>
>> Could `do` be implemented using sugar for now? Like, it expects such and
>> such methods in order for it to work. We could put it behind a feature flag
>> until we have HKT.
>>
>> ~Brendan
>>
>> On 12 Dec 2013, at 9:57 am, Zack Corr <z...@z0w0.me> wrote:
>>
>> > Yes, but Rust doesn't have HKT. I was suggesting it on this basis. I'd
>> prefer `do` as well.
>> >
>> >
>> > On Wed, Dec 11, 2013 at 5:25 PM, Ziad Hatahet <hata...@gmail.com>
>> wrote:
>> > On Tue, Dec 10, 2013 at 9:04 PM, Zack Corr <z...@z0w0.me> wrote:
>> > I think the Monadic null operator (a.k.a. safe property access
>> operator) would be pretty useful syntax sugar for mapping over option
>> types, and certainly help with the whole "option vs fail" for error
>> checking because it essentially allows monad-like functionality without
>> actually having (first-class) monads.
>> >
>> >
>> > I still think that having something like Haskell's `do`, or Scala's
>> `for` is a better way to go about this. Especially that it generalizes over
>> more than just `Option<T>`.
>> >
>> > --
>> > Ziad
>> >
>> >
>> > _______________________________________________
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>> > Rust-dev@mozilla.org
>> > https://mail.mozilla.org/listinfo/rust-dev
>>
>>
>
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