`package hello:wasm/subpackage@1.0.0` doesn't work

[jcbhmr]

In the WIT.md from https://github.com/WebAssembly/component-model/blob/main/design/mvp/WIT.md#package-declaration it seems to indicate that you can have package identifiers like this:

package hello:wasm/subpackage@1.0.0;

package-decl        ::= 'package' ( id ':' )+ id ( '/' id )* ('@' valid-semver)?

but that doesn't work with any of the wasm-tools or other tooling right now.

To reproduce:

1. create a wit folder
2. create wit/whatever.wit
3. add this code to it: package hello:wasm/subpackage@1.0.0;
4. try to wasm-tools component wit ./wit
5. it fails

error: failed to parse package: wit

Caused by:
    0: expected '{', found `/`
            --> wit/hello.wit:1:19
             |
           1 | package hello:wasm/subpackage@1.0.0;
             |                   ^

☝ this same error pops up with wkg wit fetch, the vscode syntax highlighter, etc.

i don't know if it's the WIT.md that's wrong or the wit parser in this wasm-tools project or me understanding it incorrectly 😅

[jcbhmr]

if im right about the slash package name thing not working when it should work then as a pile-on issue: the package first:second:third@1.0.0 multiple colon thing ( id ':' )+ doesn't work either

error: failed to parse package: wit

Caused by:
    0: expected '{', found ':'
            --> wit/hello.wit:1:19
             |
           1 | package hello:wasm:subpackage@1.0.0;
             |                   ^

[alexcrichton]

Ah wasm-tools generally doesn't have support for multiple package namespaces and such, so it's "expected" that this doesn't work right now. Work is definitely needed here to support this feature.