extend

DefineList.extend([name,] [static,] prototype)

Extends DefineList, or constructor functions derived from DefineList, to create a new constructor function.

var DefineList = require("can-define/list/list");

var TodoList = DefineList.extend(
  "TodoList",
  {
    "#": {type: {complete: "boolean", name: "string"}}
    availableCount: "number",
    completedCount: {
      get: function(){
        return this.filter({complete: true}).length;
      }
    },
    completeAll: function(){
      this.forEach(function(todo){
        todo.complete = true;
      })
    }
  });

var todos = new TodoList([
  {name: "dishes", complete: false},
  {name: "lawn", complete: false}
]);
todos.availableCount = 100;

todos.completeAll();
todos.completeCount //-> 2