[mappu]

Go exposes raw pointers to the programmer, so from your description i think those semantics are too rudimentary to implement Go's semantics, there would need to be a WasmGC 2.0 to make this work.

It sounds like it would be a great fit for e.g. Lua though.

[zozbot234]

I don't think Go supports any pointer arithmetic out-of-the-box? What it has in the base language is effectively references.

[pjmlp]

It does, via unsafe package, yes it does look ugly, that is on purpose.

    item := *(*int)(unsafe.Pointer(uintptr(start) + size*uintptr(i)))

A random example taken from Internet.

[zozbot234]

That's not the base language, it's an unsafe superset. There's no reason why a Wasm-GC backend for Golang should be expected to support that by default.

[pjmlp]

If it is part of the language reference it is part of the language.

Usually when language reference books used to be printed, or we used ISO languages, what is there on paper, is the language.

We are only discussing semantics, if it is hardcoded primitives, or made available via the standard library, specially in case of blessed packages like unsafe which aren't fully implemented, rather magical types for the compiler.

Hence why the only thing you will see here is mostly documentation, https://github.com/golang/go/blob/master/src/unsafe/unsafe.g...

Which is nothing new since the 1960's that there are systems languages with some way to mark code unsafe, the C linage of languages are the ones that decided to ignore this approach.

[nasretdinov]

The standard library uses unsafe for syscalls, for higher-performance primitives like strings.Builder, etc, so it's support is mandatory to run any non-trivial Go program

[mappu]

For a while the GOOS=nacl port and the Google App Engine ports of Go disallowed unsafe pointer manipulation too, so there is some precedent. Throughout some of the ecosystem you can see pieces of "nounsafe" build tag support (e.g. in easyjson).

[pjmlp]

Most programming languages that offer unsafe, either as language keyword, or meta package (unsafe/SYSTEM/UNSAFE whatever the name), have similar option, that doesn't make it less of a feature.

[zozbot234]

Somehow I don't think Wasm-GC is going to support bare metal syscalls anytime soon. That stuff all has to be rewritten anyway if you want to target WASM.

[nasretdinov]

It's not just system calls. E.g. reflection package uses unsafe too: https://github.com/golang/go/blob/master/src/reflect/value.g... . Many packages from Go standard library use unsafe one way or the other, so it's not fair to say that unsafe package is separate from the rest of the language

[mappu]

It also has an address-of operator, you can take the address of the middle of a large array.

I suppose that would be possible with fat-pointers that are reference+offset.

[yencabulator]

You can get a pointer inside a struct ("interior pointers") without pointer arithmetic.