An idiom borrowed from React that allows Mithril components to skip view diffing if their `shouldUpdate` function returns falsey when passed view args

component_shouldUpdate.js

import remember from 'funes'

const retainer = { subtree : 'retain' }

export default remember.bind(
	component => {
		return 'shouldUpdate' in component
			? {
				...component,
				view : ( ...args ) =>
					component.shouldUpdate( ...args )
					? component.view( ...args )
					: retainer
			}
			: component 
	}
)