On Jan 10, 2014, at 10:18 AM, Patrick Walton <[email protected]> wrote:
> On 1/10/14 7:20 AM, Nakamura wrote:
>> I'm new to rust, and tried going through some of the examples from the
>> OS class[0] that was taught in rust. However, I got tripped up by the
>> exercise, "make a function that takes an integer n and another function
>> |x| -> x, and returns a function that is n applications of the original
>> function."
>>
>> I've been trying to see what the limits of rust are if you are using it
>> without the runtime/managed pointers etc, and it seems like I stumble
>> against one of the limits when trying to return functions. The big
>> question is where to allocate the new function I want to return.
>
> Rust won't automatically allocate closed-over variables on the heap. This
> limits the ability to write code like this naturally, but you get the benefit
> that all allocations are immediately visible and under the control of the
> programmer.
>
> I would not suggest trying to use managed pointers for this. Instead I would
> suggest `proc`, which is allocated on the exchange heap and can close over
> variables. This should be sufficient for the question as posed, as long as
> the "another function" has a `'static` bound (`'static |x| -> x`).
Procs can only be called once, though, which is a bit of a limitation.
Does ~|| -> T no longer exist?
-Kevin
_______________________________________________
Rust-dev mailing list
[email protected]
https://mail.mozilla.org/listinfo/rust-dev
