rum does not officially support non-symbol attributes, and thus officially precludes certain classes of attributes from being generated

[jf]

As per https://github.com/tonsky/rum/blob/gh-pages/CHANGELOG.md#090, Starting with 0.9.0, Rum will adopt “There’s Only One Way To Do It” policy. All attributes MUST be specified as kebab-cased keywords:. This is fine for your typical tag attribute; but results in issues with some other attributes like Alpine.js uses:

":"-prefixed attributes

[:div {::class "open ? '' : 'hidden'"}]
-> produces <div></div>

"@"-prefixed attributes

[:div {:@mouseenter "alert('Hello!')"}] gives an error

Having said all this, it would appear that giving the required attributes in string form works:

[:div {":class" "open ? '' : 'hidden'"}]
-> produces <div :class="open ? &#x27;&#x27; : &#x27;hidden&#x27;"></div> (let's ignore the escaping of the attribute value for now)

[:div {"@mouseenter" "alert('Hello!')"}]
-> produces <div @mouseenter="alert(&#x27;Hello!&#x27;)"></div> (similarly let's ignore the escaping of the attribute value for now; I will file another issue for that)

I believe that officially supporting the string form for these use cases is the way to go, and if so, it would be good to note this down in the README.