Hands-On Design Patterns and Best Practices with Julia

The prototype pattern

The prototype pattern is used to create new objects by cloning fields from an existing object, or the prototype object. The idea is that some objects are difficult or time-consuming to construct, so it would be useful to make a copy of the object and call it a new one by making small modifications.

As Julia keeps data and logic separate, making copies of objects is really the same as duplicating the content. That sounds easy, but we should not overlook the difference between a shallow copy and a deep copy.

A shallow copy of an object is merely an object with all the fields copied from another object. A deep copy of an object is created by recursively going into the fields of the object and copying their underlying fields ...