WebAssembly

stack-switching

WebAssembly2023–2026

WebAssembly / stack-switching

stack-switching

A repository for the stack switching proposal.

Web Development

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6Distinct people

6Mentions

0Explicit recommenders

220GitHub stars

REPOSITORY AT A GLANCE

What to know before exploring

What it is

A repository for the stack switching proposal.

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 11:56:56 AM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year6 dated mentions

Observed mentions: 2023-09-24 12:05:48 UTC to 2026-07-25 08:18:08 UTC.

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges

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Period	Start (UTC)	End (exclusive, UTC)	Mentions	Comments
2023	2023-01-01 00:00:00 UTC	2024-01-01 00:00:00 UTC	3	3
2024	2024-01-01 00:00:00 UTC	2025-01-01 00:00:00 UTC	1	1
2025	2025-01-01 00:00:00 UTC	2026-01-01 00:00:00 UTC	1	1
2026 (partial)	2026-01-01 00:00:00 UTC	2027-01-01 00:00:00 UTC	1	1

What Hacker News says

6 sources

faldor20·Jul 25, 2026

It seems like a bit of a shame that wasm got support for exceptions but doesn't support effects which are a generalisation of the same concept. https://wasmfx.dev/ I'm guessing this may be because exceptions exclusively require stack unwinding where as effects require full stack switching. Seems like there is still progress on that though which gives hope https://github.com/WebAssembly/stack-switching/blob/main/pro...

In GC and Exceptions in Wasmtime

jauntywundrkind·Jan 14, 2025

Wow, that's a very fun reply! Nice. Fingers crossed that the Stack Switching spec gets adopted & serves Guile Hoot's needs for fibers. https://github.com/WebAssembly/stack-switching

In The Shepherd 1.0.0 released

marianoguerra·Feb 18, 2024

Here's a good explanation: https://github.com/WebAssembly/stack-switching/blob/main/pro...

In WASM Instructions

asplake·Nov 8, 2023

Enjoyed the linked (more detailed) explainer: https://github.com/WebAssembly/stack-switching/blob/main/pro...

In WasmFX: Effect Handlers for WebAssembly

infogulch·Nov 8, 2023

I first heard of algebraic effects in a presentation about Unison recorded at Strangeloop. Realizing that exceptions, async, generators, and continuations could all be unified and implemented on top of one language feature was mind expanding. It looks like the juicy details are in the Explainer: https://github.com/WebAssembly/stack-switching/blob/main/pro...

In WasmFX: Effect Handlers for WebAssembly

flohofwoe·Sep 24, 2023

"Fibers", "green threads", "stack switching", "cooperative multitasking" are essentially all the same thing, they all rely on being able to switch execution context by switching to a different stack within the same OS thread. As such they can be implemented either in (CPU/OS-specific) user code or in "OS APIs" (like the Windows Fiber functions). Only downside of the technique is that it cannot be implemented in WASM (and maybe some other esoteric runtime environments), because WASM has separate data- and call-stacks and the call stack is not accessible from within the WASM virtual machine (while 'async-await' which relies on code transformation done by the compiler can be implemented in WASM just fine). There is a 'stack-switching proposal' for WASM though, but I don't know what's the state of that: https://github.com/WebAssembly/stack-sw

Read the rest

itching

In Fiber in C++: Understanding the Basics