I'm glad to see packages such as this appearing, but I'm also curious to see if anyone considered a much more efficient HTML renderer that relies on macros instead of result builders. I'll post a few ideas here that I had on my wishlist for a long time for a macro-based HTML rendering library.
With function body macros there's no need to pollute the global namespaces with a separate function for each HTML tag.
IMO for this to be viable in the embedded mode and in applications caring about performance (both Wasm and microcontrollers), it also has to evaluate as much as possible at compile-time and minimize the amount of allocations.
E.g. I'd expect this
div {
p { "Look how pretty." }
}
to be compiled down into a single string
"<div><p>Look how pretty.</p></div>"
instead of two function calls (to both div and p) each allocating a temporary string and concatenating them at compile-time.
Also, with function body macros one would be able to support arguments passed in any order, i.e. both
p(class: "greeting", id: "paragraph")
and
p(id: "paragraph", class: "greeting")
This way a library doesn't need to define helper enums with case .class or multiple overloads for p function that support all combinations of arguments.