[m-users.] IO argument clobbering

[Sean Charles (emacstheviking)]

Zoltan, Volker...... yes!

That makes it compile and run just fine.... I am not sure I fully comprehend but I will go and RTFM some more, that might help.

Thank you both.


> On 17 Jul 2023, at 15:37, Zoltan Somogyi <zoltan.somogyi at runbox.com> wrote:
> 
> 
> On 2023-07-17 16:27 +02:00 CEST, "Sean Charles (emacstheviking)" <objitsu at gmail.com> wrote:
>> :- type callback == (pred(world, world, io, io)).
>> :- inst callback == (pred(in, out, di, uo) is det).
>> 
>> :- pred run_loop(
>>    callback::in, world::in, world::out, io::di, io::uo
>> ) is det.
> 
> Without compileable example code I cannot be sure, but I think
> the problem is the "callback::in" in the declaration of run_loop.
> What happens when you replace it with "callback:in(callback)"?
> The mode checker needs this to tell it the mode of the higher order arg.
> 
> Zoltan.