Basic concepts

Abstract

Before diving into the depths of the Common Lisp condition system, we will first introduce three programming concepts that collectively form the foundation of the condition system: dynamic variables, performing non-local transfers of control, and lexical closures. Understanding these lower-level techniques is important to understanding the functioning of the CL condition system as a higher-level mechanism; therefore, readers who are already proficient with these techniques may consider skipping the relevant sections and continue from the next chapter of the book.