In a dynamically scoped language, the determination of the declaration to which a reference is bound requires run-time information. In a typical implementation of dynamic scoping, it is the calling sequence of procedures, and not their lexical relationship to each other, that is used to determine the declaration to which each reference is bound. While Scheme uses lexical scoping, for the purpose of demonstration, we use the following Scheme expression to demonstrate dynamic scoping:
In this expression we see nonlocal references to x and y in the definition of proc2 on line 2, which does not provide declarations ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.
