Stream: wasm

Topic: WIT and semicolons

Alex Crichton (Sep 26 2023 at 14:30):

As a heads up the plan is to add semicolons to the WIT text format in the near future. With the spec updated I've updated the wasm-tools repository and hope to publish that today and start integrating it into tools. This means that once that change starts propagating you can start putting semicolons in WIT files.

To avoid breaking too much this is a bit of a phased rollout:

• The wit-parser 0.11.2 release will support semicolons in WIT, but not require it.
• Any tooling which depends on that version of wit-parser can use semicolons
• You can set WIT_REQUIRE_SEMICOLONS=1 in CI or locally to simulate what will happen when they're required

Eventually in the future we'll publish a version of wit-parser that requires semicolons by default but still supports optional semicolons via WIT_REQUIRE_SEMICOLONS=0. Then a bit further in the future the env var will be removed and semicolons will always be required.

Alex Crichton (Sep 26 2023 at 14:32):

My rough idea for a timeline here is:

• By October 20 all tooling will support semicolons. This is the Wasmtime 14 release date.
• On November 20 all tooling will require semicolons by default, this is the Wasmtime 15 release date.

Alex Crichton (Sep 26 2023 at 14:32):

• On December 20 all tooling won't have an option to parse non-semicolon-using WITs, this is Wasmtime 16

Alex Crichton (Sep 26 2023 at 14:34):

With exact dates being a bit fungible, so for example wasm-tools will on November 5 require semicolons by default since that will then be integrated into Wasmtime for the release later that month. The hope though is that by smearing this over a few months it should reduce churn where if you hit breakage it should be straightforward to fix without requiring everything be updated all at once. In theory. We'll see!

Last updated: Dec 23 2024 at 12:05 UTC