Cycle.js prevenDefault intent

https://github.com/staltz/cycle/

HTML

<script src="https://rawgit.com/staltz/cycle/v0.8.1/dist/cycle.js"></script>
<div id="cycleapp"></div>

JavaScript

var h = Cycle.h;
var Rx = Cycle.Rx;

var Model = Cycle.createModel(function (intent) {
    return {
        toggled$: intent.get('toggle$').startWith(false)
    };
});

var View = Cycle.createView(function (model) {
    return {
        vtree$: model.get('toggled$')
            .map(function (toggled) {
                return h('div', [
                    h('input', {
                        onclick: 'checkboxClick$',
                        attributes: {
                            type: 'checkbox'
                        }
                    }),
                    h('span', String(toggled ? 'YEEES' : 'nooo')),
                    h('span', String(" yeah"))
                ]);
            })
    };
});

var Intent = Cycle.createIntent(function (view) {
    return {
        toggle$: view.get('checkboxClick$')
            .map(function (ev) {
                ev.preventDefault(); // comment me and learn something
                return true;
            })
            .scan(function (prev, curr) { return !prev; })
    };
});

var Renderer = Cycle.createRenderer('#cycleapp');

Renderer.inject(View);
Intent.inject(View);
View.inject(Model);
Model.inject(Intent);