pointer access across await

[ceu-lang]

pointer access across await

[fsantanna]

The pointer assignment/use is crossing a "par/or" rejoin, what is currently not allowed.
We may accept this program in the future, given that the assignment/rejoin/use occurs in the same reaction.
How difficult is to rewrite your code to get rid of the error?
I guess you wrote a simpler version and compiling it is not as simple as moving the "if c then..." to inside the "par/or".

[Johnicholas]

The general pattern is: An organism is trying to acquire a pointer to something (by awaiting). The organism also wants to engage in an "idling" activity, which takes up as much time as necessary, but should be terminated when the organism can progress in its actual task.

Maybe this snippet conveys the (more complicated real task) more convincingly.

var Foo* ptr = null;
par/or do
_idle();
await FOREVER;
with
ptr = await generator;
end
_assert(ptr);
watching ptr do
_something();
end

I'll keep looking for a rewrite that doesn't involve crossing a par/or rejoin; it's probably a failure of imagination on my part.

[fsantanna]

Fair enough.

As a workaround, you can declare Foo as a "plain" pointer:

var Foo[] ptr = null;

(I also have a "TODO" with a similar pattern and workaround.)

[fsantanna]

Sorry, this is older than 1 year!

Using escape, you can assign safely to the pointer that syntactically crosses a par:

var u8&& ptr =
    par do
        //_idle();
        await FOREVER;
    with
        await 1s;
        escape null;
    end;
escape ptr == null;  // yields 1