Late Binding and Caching

Abstract

Late binding is binding that happens at run time, and it is the essence of what makes a language dynamic. When binding happens at run time as opposed to compile time, it’s usually several orders of magnitude slower. And that’s why the DLR has a mechanism to cache the late-binding results. The caching mechanism is as vital as air to a framework like the DLR, and it’s based on an optimization technique called polymorphic inline caching. Although caching is not a feature you would normally use directly, it is always there working for you behind the scenes. The DLR uses what are called binders to do late binding. These binders have two main responsibilities—caching and language interoperability. In this chapter, we are going to look at the caching aspect of binders. The next chapter will explore their role in language interoperability.