move snabbdom into libs/

libs/snabbdom/src/thunk.ts

@@ -0,0 +1,64 @@
+import {VNode, VNodeData} from './vnode';
+import {h} from './h';
+
+export interface ThunkData extends VNodeData {
+  fn: () => VNode;
+  args: Array<any>;
+}
+
+export interface Thunk extends VNode {
+  data: ThunkData;
+}
+
+export interface ThunkFn {
+  (sel: string, fn: Function, args: Array<any>): Thunk;
+  (sel: string, key: any, fn: Function, args: Array<any>): Thunk;
+}
+
+function copyToThunk(vnode: VNode, thunk: VNode): void {
+  thunk.elm = vnode.elm;
+  (vnode.data as VNodeData).fn = (thunk.data as VNodeData).fn;
+  (vnode.data as VNodeData).args = (thunk.data as VNodeData).args;
+  thunk.data = vnode.data;
+  thunk.children = vnode.children;
+  thunk.text = vnode.text;
+  thunk.elm = vnode.elm;
+}
+
+function init(thunk: VNode): void {
+  const cur = thunk.data as VNodeData;
+  const vnode = (cur.fn as any).apply(undefined, cur.args);
+  copyToThunk(vnode, thunk);
+}
+
+function prepatch(oldVnode: VNode, thunk: VNode): void {
+  let i: number, old = oldVnode.data as VNodeData, cur = thunk.data as VNodeData;
+  const oldArgs = old.args, args = cur.args;
+  if (old.fn !== cur.fn || (oldArgs as any).length !== (args as any).length) {
+    copyToThunk((cur.fn as any).apply(undefined, args), thunk);
+    return;
+  }
+  for (i = 0; i < (args as any).length; ++i) {
+    if ((oldArgs as any)[i] !== (args as any)[i]) {
+      copyToThunk((cur.fn as any).apply(undefined, args), thunk);
+      return;
+    }
+  }
+  copyToThunk(oldVnode, thunk);
+}
+
+export const thunk = function thunk(sel: string, key?: any, fn?: any, args?: any): VNode {
+  if (args === undefined) {
+    args = fn;
+    fn = key;
+    key = undefined;
+  }
+  return h(sel, {
+    key: key,
+    hook: {init: init, prepatch: prepatch},
+    fn: fn,
+    args: args
+  });
+} as ThunkFn;
+
+export default thunk;