Error message on html! macro with multiple roots

[derekdreery]

If you do

html!(
  <div>"First element"</div>
  <div>"Illegal second element"</div>
)

you get

error: proc-macro derive panicked
   --> src/views.rs:122:5
    |
122 | /     html!(
123 | |         <div class="prices-table-title" id="products-cupcakes">"cupcakes"</div>
124 | |         <div class="prices-image" id="cookies-cream-cupcakes">""</div>
125 | |         <div class="prices-table">
...   |
134 | |             <br/>"Trial flavours available upon request"</div>
135 | |     )
    | |_____^
    |
    = help: message: index out of bounds: the len is 0 but the index is 0
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

Maybe the panic could say "all invocations of the html! macro must have exactly 1 root element".

[derekdreery]

^^ You don't get that exact error - I copied it from a trial website I'm making :'D

[bodil]

I'm wondering if I should try and get it to actually accept this and return an iterator of elements - like, there's the <> syntax for this sort of thing in JSX (#18) but that's strictly just to tell the JS parser that a JSX block is starting, but the macro invocation serves that purpose here.

[derekdreery]

That would be awesome, currently I'm doing something like

fn view_fn() -> Vec<Box<dyn Node>> {
    return vec![
        html!(<p>"Part one"</p>),
        html!(<p>"Part two"</p>),
    ];
}