SOURCE

(function () { 
    var moduleMap = {}; 
    var fileMap = {}; 
 
    var noop = function () { 
    }; 
 
    var thin = { 
        define: function(name, dependencies, factory) { 
            if (!moduleMap[name]) { 
                var module = { 
                    name: name, 
                    dependencies: dependencies, 
                    factory: factory 
                }; 
 
                moduleMap[name] = module; 
            } 
 
            return moduleMap[name]; 
        }, 
 
        use: function(name) { 
            var module = moduleMap[name]; 
 
            if (!module.entity) { 
                var args = []; 
                for (var i=0; i<module.dependencies.length; i++) { 
                    if (moduleMap[module.dependencies[i]].entity) { 
                        args.push(moduleMap[module.dependencies[i]].entity); 
                    } 
                    else { 
                        args.push(this.use(module.dependencies[i])); 
                    } 
                } 
 
                module.entity = module.factory.apply(noop, args); 
            } 
 
            return module.entity; 
        }, 
 
        require: function (pathArr, callback) { 
            for (var i = 0; i < pathArr.length; i++) { 
                var path = pathArr[i]; 
 
                if (!fileMap[path]) { 
                    var head = document.getElementsByTagName('head')[0]; 
                    var node = document.createElement('script'); 
                    node.type = 'text/javascript'; 
                    node.async = 'true'; 
                    node.src = path + '.js'; 
                    node.onload = function () { 
                        fileMap[path] = true; 
                        head.removeChild(node); 
                        checkAllFiles(); 
                    }; 
                    head.appendChild(node); 
                } 
            } 
 
            function checkAllFiles() { 
                var allLoaded = true; 
                for (var i = 0; i < pathArr.length; i++) { 
                    if (!fileMap[pathArr[i]]) { 
                        allLoaded = false; 
                        break; 
                    } 
                } 
 
                if (allLoaded) { 
                    callback(); 
                } 
            } 
        } 
    }; 
 
    window.thin = thin; 
})();

/**
* 例子部分
*/
thin.define("constant.PI", [], function() { 
    return 3.14159; 
}); 
 
thin.define("shape.Circle", ["constant.PI"], function(pi) { 
    var Circle = function(r) { 
        this.r = r; 
    }; 
 
    Circle.prototype = { 
        area : function() { 
            return pi * this.r * this.r; 
        } 
    } 
 
    return Circle; 
}); 
 
thin.define("shape.Rectangle", [], function() { 
    var Rectangle = function(l, w) { 
        this.l = l; 
        this.w = w; 
    }; 
 
    Rectangle.prototype = { 
        area: function() { 
            return this.l * this.w; 
        } 
    }; 
 
    return Rectangle; 
}); 
 
thin.define("ShapeTypes", ["shape.Circle", "shape.Rectangle"], function(Circle, Rectangle) { 
    return { 
        CIRCLE: Circle, 
        RECTANGLE: Rectangle 
    }; 
}); 
 
thin.define("ShapeFactory", ["ShapeTypes"], function(ShapeTypes) { 
    return { 
        getShape: function(type) { 
            var shape; 
 
            switch (type) { 
                case "CIRCLE": { 
                    shape = new ShapeTypes[type](arguments[1]); 
                    break; 
                } 
                case "RECTANGLE":  { 
                    shape = new ShapeTypes[type](arguments[1], arguments[2]); 
                    break; 
                } 
            } 
 
            return shape; 
        } 
    }; 
}); 
 
var ShapeFactory = thin.use("ShapeFactory"); 
alert(ShapeFactory.getShape("CIRCLE", 5).area()); 
alert(ShapeFactory.getShape("RECTANGLE", 3, 4).area());