Something like this would fit in perfectly with the new
For example, as
Currently, I only really have one problem with the new (very powerful)
task library… Technically, I can’t actually implement a real task architecture, because I can’t cancel a task.
In other words, the
task library in its current form is less of a full fledged task library and more of a powerful extension of the coroutine library with some extra thread scheduling goodies.
local thread = coroutine.create(someTaskFunction)
-- We don't want to do any more work, maybe this is a user action and the user stopped it, so, cancel the task
I would absolutely love the ability to implement full fledged tasks. I could for example refactor a lot of the input code in my game to not look like this:
if not self.Active then
-- a yield
if not self.Active then
I did a little research on this, for people that are interested in the extra details:
Task cancellation & how its implemented in other languages
Summary of different methods of task cancellation
There are two ways of involuntarily ending threads/tasks. One is to just forcefully end a task, which, is currently impossible without abusing BaseScripts and
.Disabled. This is the sort of cancellation that Roblox should absolutely provide support for.
The other way is throwing an error at yield points. This is possible in luau by overriding every point where a thread can yield (which is what my script sandbox does), but, built in Roblox functions don’t support it which results in unwanted engine errors.
A thread has to poll for whether or not it should be cancelled. Currently, this is the easiest way to do this in luau, but, Roblox functions don’t support this, also resulting in unwanted engine errors depending on implementation.
Implementations of task cancellation in other languages
Coroutines and Tasks — Python 3.9.6 documentation
Python allows for coroutines to be ran and cancelled at any time, and provides an ability to shield code from being cancelled.
This is the sort of architecture that would be perfect in Roblox.
C++11 doesn’t have any official or built in way to safely cancel threads/tasks, but, the above Stackoverflow answer outlines several ways that the end user can implement cancellation.
This discusses two ways of doing thread cancellation (with varying safety levels) without requiring the thread body to voluntarily check a cancellation condition. The third way is the same way the two below languages implement task cancellation.
C# and Java
Task Cancellation | Microsoft Docs
Java SE 9 & JDK 9
C# and Java both do the reverse, which, is more appropriate for lower level languages, and requires that tasks poll when they want to cancel. Luau doesn’t natively support task cancellation from the user-level which results in undesired engine errors if a thread resumption is queued.