Error: `expected parenthesis in `#[parse_terminated(...)]``

[bravely-beep]

The docs say #[parse_terminated] takes no arguments, but attempting to use it gives the error:

expected parenthesis in `#[parse_terminated(...)]`

Example:

mod kw {
    syn::custom_keyword!(nop);
}

#[derive(Parse)]
pub struct Program {
    #[parse_terminated]
    instructions: Punctuated<Instruction, Token![,]>,
}

#[derive(Parse)]
pub enum Instruction {
    #[peek(kw::nop, name = "nop")]
    Nop,
}

[naerbnic]

I'm also getting this error under the same circumstances.

A temporary workaround is using #[call(Punctuated::parse_terminated)], which seems to work as well.

[jktechs]

Had the same issue and came up with the same solution. Looking through the code it seems to be trying to parse a syn::Path for some reason guessing the docs are a bit behind new features being worked on.

[jktechs]

So the funny thing is they tried to give more options by allowing you to provide a custom parse function only if you provide one rust gives you the error that two args were expected because on line 433 of fields.rs it does:

quote_spanned! { path.span()=> #input_source.parse_terminated(#path)? }

but that function need the separator aswel. So no args makes this crate error. One arg makes rust error and two or more makes this crate error again. so its not possible to uses this attribute in the current state.