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WIT: consider dropping unions #236
Description
Unions are uniquely challenging to implement in bindings because their cases do not have kebab-case names. See for example the wit-bindgen Rust generator's awkward solution to this: https://github.com/bytecodealliance/wasmtime/blob/367bdc8c66df62d6854966a90564b42692a3f023/crates/wit-bindgen/src/rust.rs#L317
Rather than expecting each bindings language to come up with a generic naming scheme to handle unions, I think we should put the onus on WIT authors to select reasonable case names on an equivalent variant.
A quick Github search (and review of WASI) suggests that unions are not currently in use outside of tests and samples.
Activity
alexcrichton commentedon Aug 21, 2023
Personally I'd agree with this and would be in favor 👍
lukewagner commentedon Aug 21, 2023
I'd be fine dropping them too. Initially they were added because the proposal spawned out of Web IDL, which has
union. But yeah, I can see how it ends up being a special case for many languages, especially the statically-typed ones.guybedford commentedon Aug 21, 2023
Even in JavaScript, they're still tagged awkwardly and don't actually correspond to the IDL / TypeScript equivalents, so this seems fine to me as well.