LightTable的结构（一）

LightTable使用clojurescript来生成js，然后使用 node-webkit 来处理UI

clojurescript非常适合做抽象程度很高的页面和编辑逻辑结构设计，

最近会对整体进行分析整理一个大题的结构图

程序的入口在lt.objs.app@init

可以看到init做了几件事情进行初始化

(defn init []
  (object/raise app :deploy)
  (object/raise app :pre-init)
  (object/raise app :init)
  (object/raise app :post-init)
  (object/raise app :show))

　　而操作的对象，app的初始化在：　

(object/object* ::app
                :tags #{:app :window}
                :delays 0
                :init (fn [this]
                        (ctx/in! :app this)))

(def app (object/create ::app))

app是object/object*和object/create一起生成的

(defn object* [name & r]
  (-> (apply make-object* name r)
      (store-object*)
      (handle-redef)))

(defn make-object* [name & r]
  (let [obj (merge {:behaviors #{} :tags #{} :triggers [] :listeners {} ::type name :children {}}
                   (apply hash-map r))]
    obj))

(defn store-object* [obj]
  (add obj)
  obj)

(defn add [obj]
  (swap! object-defs assoc (::type obj) obj))

　　

(defn create [obj-name & args]
  (let [obj (if (keyword? obj-name)
              (@object-defs obj-name)
              obj-name)
        id (or (::id obj) (swap! obj-id inc))
        inst (atom (assoc (dissoc obj :init)
                     ::id id
                     :args args
                     :behaviors (set (:behaviors obj))
                     :tags (set (conj (:tags obj) :object))))
        inst (store-inst inst)
        _ (merge! inst (update-listeners inst))
        content (when (:init obj)
                  (apply (:init obj) inst args))
        content (if (vector? content)
                  (crate/html content)
                  content)
        final (merge! inst {:content content})]

    (add-watch inst ::change (fn [_ _ _ _]
                               (raise inst :object.change)))
    (raise* inst (trigger->behaviors :object.instant (:tags @inst)) nil)
    (raise inst :init)
    inst))

　　

object/object*生成了一个hash-map的对象，对象包含了behavior，tag之类的属性，每个object对应一个唯一的名字，存在object-defs这个atom对象里，这个object-defs用于记录所有的类对象的定义

object/create中，先是通过(@object-defs obj-name)来获取object，然后对object做一些创建的工作，

inst是instance的缩写，采用了类似javascript里的clone的方式来创建一个object的instance