If not, then transformations have to be performed in the mapping phase.
如果没有，则在映射阶段必须执行转换。
Now, listen to the melody generated by applying this mapping to rule 150.
现在，聆听把映射应用到150号规则所产生的旋律。
I was pleasantly surprised how I could achieve this type of dynamic mapping with so little code.
我惊喜地发现，我可以用很少的代码实现这种类型的动态映射。