Partial attributes

[luwes]

Research if partial attributes are possible and worth adding.

[luwes]

It would need to be handled somewhere in the logic of sinuous/htm.

Currently htm does support partial attributes https://github.com/developit/htm/releases/tag/2.2.0 but they are concatenated. An observable, essentially a function, and a string can't be joined like that.

The solution would be something like detect whether one part is an observable, wrap both parts in a closure.

html`<div class="margin${side}"></div>`

becomes

h('div', {
	class: () => 'margin' + side()
})