HTML comments

The third kind of comment is specific to Asteracea and does affect program output:

#![allow(unused)]
fn main() {
asteracea::component! {
  HtmlCommented()()

  <!-- "This is an HTML comment." -->
}
}

<!--This is an HTML comment.-->

The double quotes are a Rust limitation: Since Rust tokenises macro input, a string literal is required to extract raw text.

You can use a multiline string to easily write a multiline HTML comment:

#![allow(unused)]
fn main() {
asteracea::component! {
  HtmlCommented()()

  <!-- "
    This comment spans mul-
    tiple lines, I hope it is
    not too annoying.
  " -->
}
}

<!--
    This comment spans mul-
    tiple lines, I hope it is
    not too annoying.
  -->