tag toggle
	prop param
	prop disabled

	css cursor:pointer cursor.disabled:default

	def render
		<self.activated=R.params[param] .disabled=disabled @click.if(!disabled)=R.toggle(param)><slot>

tag ref-f # f - forget current params in new destination
	prop view
	prop target = {}
	prop go

	def render
		let link = go || url
		<self[d:inline]><a.active=(R.to_path! == link) href=link @click.prevent=R.go(link)><slot>

	get url
		R.to_path view, target

tag ref < ref-f
	get url
		#target = JSON.parse JSON.stringify(target) # duplicate object
		#target[k] ||= v for own k, v of R.safe_params
		R.to_path view, #target

tag not_found
	<self><h1> "Page not found :("