Context cancellation (and it's propagation) is one of the best features in Go.

Is there any equivalent in major popular languages like Python, Java, or JS of this?

▲ nh2 an hour ago | parent | next [-]

Haskell is the king of cancellation. Using asynchronous exceptions, you can cancel anything, anytime, with user -defined exception types so you know what the cancellation reason is.

Example:

    maybeVal <— timeout 1000000 myFunction

Some people think that async exceptions are a pain because you nerd to be prepared that your code can be interrupted any time, but I think it's absolutely worth it because in all the other languages I encounter progress bars that keep running when I click the cancel button, or CLI programs that don't react to CTRL+C.

In Haskell, cancellability is the default and carries no syntax overhead.

This is one of the reasons why I think Haskell is currently the best language for writing IO programs.

▲ ndriscoll 6 hours ago | parent | prev | next [-]

ZIO in Scala tracks this sort of thing except you don't have to remember to pass around or select on the ctx (it's just part of the fibre/"goroutine"); if it's cancelled, the fibre and its children just stops the next time it yields (so e.g. if it "selects" on anything or does any kind of IO).

▲ deathanatos 6 hours ago | parent | prev | next [-]

Python async tasks can be cancelled. But, I don't think you can attach must context to the cancel (I think you can pass a text message), so it would seem the argument of what go suffered from would apply.

(I also think there's some wonkiness with and barriers to understanding Python's implementation that I don't think plagues Go to quite the same extent.)

▲ lifis 6 hours ago | parent | prev | next [-]

All mainstream languages have it in one or more forms (either direct task I/O cancellation, or cancellation tokens or I/O polling that can include synthetic events) since otherwise several I/O patterns are impossible

▲ perfmode 6 hours ago | parent | prev | next [-]

one of the reasons why i love writing control planes in Go.

▲ nnx 6 hours ago | parent | prev | next [-]

in JS, signals and AbortController can replicate some of the functionality but it's far less ergonomic than Go.

https://github.com/ggoodman/context provides nice helpers that brings the DX a bit closer to Go.

▲ drdaeman 6 hours ago | parent | prev | next [-]

C# has CancellationToken, but it’s just for canceling operations, not a general purpose context.

▲ richbell 6 hours ago | parent | prev | next [-]

Kotlin Coroutine's structured concurrency. Cancelling a parent automatically cancels child jobs, unless explicitly handled not to. https://kotlinlang.org/docs/coroutines-basics.html

	▲	tadfisher 4 hours ago \| parent [-]
		Stupidly, child cancellation cancels the parent scope as well, unless the scope opts out by including SupervisorJob.

▲ Quekid5 5 hours ago | parent | prev | next [-]

Java's Virtual Threads (JVM 21) + the Structured Concurrency primitives (not sure exactly what's available in Java 21+) do this natively.

Also, a sibling poster mentioned ZIO/Scala which does the Structured Concurrency thing out of the box.

▲ gzread 7 hours ago | parent | prev [-]

Not really, since they don't have `select`

There's a stop_token in some Microsoft C++ library but it's not nearly as convenient to interrupt a blocking operation with it.