If blocks raise parse error in attributes

[eyeseast]

I've run into this a couple times where I want to conditionally add a class name, but svelte raises a ParseError when I try to use an if block inside class.

Here's a broken example: https://svelte.technology/repl?version=1.53.0&gist=287434fece22488b8af3aba0edb73988

Using a ternary works: https://svelte.technology/repl?version=1.53.0&gist=67ccedb4c7cc8e661bc61bb75c40e50c

This may be simply a documentation issue. Using a ternary is fine, but I forget and run into that same error every time.

[Conduitry]

Yeah regular {{tags}} are the only things that are intended to be used in attribute values. I'll open an issue in the site repo and close this one. Thanks!