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                // since we're loading from <script> tags, pull out a few shorthand values
var compile = SurplusCompiler.compile,
    data = SurplusDataMixin.default,
    SArray = SArray.default;

var Todo = t => ({               // our Todo constructor
       title:,   // properties are data signals
    todos = SArray([]),          // our array of todos
    newTitle =""),       // title for new todos
    addTodo = () => {            // push new title onto list
        todos.push(Todo({ title: newTitle(), done: false }));
        newTitle("");             // clear new title
    // codepen can't preprocess code, so compile and eval here
    view = eval(compile(`
            <h3>Minimalist ToDos in Surplus</h3>
            <input type="text" placeholder="enter todo and click +" fn={data(newTitle)}/>
            <a onClick={addTodo}> + </a>
            { =>     
                    <input type="checkbox" fn={data(todo.done)}/>
                    <input type="text" fn={data(todo.title)}/>
                    <a onClick={() => todos.remove(todo)}>&times;</a>

if (localStorage.todos) // load stored todos on start
S(() =>                 // store todos whenever they change
    localStorage.todos = JSON.stringify(todos().map(t => 
        ({ title: t.title(), done: t.done() }))

document.body.appendChild(view); // add view to document