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所有的节点的transform方法都对应同一个函数:
node.DEFMETHOD("transform", function(tw, in_list){
var x, y;
tw.push(this);
if (tw.before) x = tw.before(this, descend, in_list);
if (x === undefined) {
if (!tw.after) {
x = this;
descend(x, tw);
} else {
tw.stack[tw.stack.length - 1] = x = this.clone();
descend(x, tw);
y = tw.after(x, in_list);
if (y !== undefined) x = y;
}
}
tw.pop();
return x;
});
不同的是每个节点可以有不同的descend方法
AST_Node的descend方法为一个空函数
以下节点有自定义的descend方法
AST_LabeledStatement,AST_SimpleStatement,AST_Block,AST_DWLoop,AST_For,AST_ForIn,
AST_With,AST_Exit,AST_LoopControl,AST_If,AST_Switch,AST_Case,AST_Try,AST_Catch,
AST_Definitions,AST_VarDef,AST_Lambda,AST_Call,AST_Seq,AST_Dot,AST_Sub,
AST_Unary,AST_Binary,AST_Conditional,AST_Array,AST_Object,AST_ObjectProperty
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原文地址：http://www.cnblogs.com/gniavaj/p/4243677.html
